Wednesday, December 31, 2008

shows human groups with the deepest roots in southeastern Europe

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Message: Sorenson Molecular Genealogy Foundation And International Scientific Team Show Prehistoric Foragers from Southeastern Europe Adopted Farming, Weren't Replaced by Middle Eastern Colonizers
12/30/2008

SALT LAKE CITY--(BUSINESS WIRE)--Genetic research by the Sorenson Molecular Genealogy Foundation (SMGF) and scientists from ten organizations in Europe and the U.S. shows human groups with the deepest roots in southeastern Europe were not pushed out by an incoming wave of farmer-colonists as agriculture first spread into Europe. Instead, indigenous Europeans with a hunting and gathering lifestyle adopted agriculture when it was introduced by settlers from the Middle East. The study was published in the Dec. 24, 2008 online issue of European Journal of Human Genetics.

Monday, December 29, 2008

ADN mitocondrial

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Message: Source: http://es.wikipedia.org/wiki/ADN_mitocondrial

El ADN mitocondrial, es el material genético de las mitocondrias, los orgánulos que generan energía para la célula. El ADN mitocondrial se reproduce por sí mismo semi-autonómicamente cuando la célula eucariota que ocupa se divide.

Este ADN, al igual que los ADN bacterianos, es una molécula bicatenaria, circular, cerrada, sin extremos. Tiene un tamaño de 16.569 pares de bases, conteniendo un pequeño número de genes, distribuidos entre la cadena H y la cadena L. Cada mitocondria contiene entre 2 y 10 copias de la molécula de ADN. En él están codificados dos ARN ribosómicos, 22 ARN de transferencia y 13 proteínas que participan en la fosforilación oxidativa. Estos genes mitocondriales son:

* genes de ARNts
* genes de ARNrs
* genes de ARNms, codificando para diversas proteínas

El número de genes en el ADN mitocondrial es de 37,[1] frente a los 20.000 - 25.000 genes del ADN cromosómico nuclear humano.

La herencia mitocondrial es matrilineal, es decir, el ADN mitocondrial se hereda solo por vía materna. Tradicionalmente se ha considerado que cuando un espermatozoide (célula reproductora masculina) fecunda un óvulo (célula reproductora femenina) se desprende de su cola y de todo su material celular, excepto del núcleo que contiene el ADN nuclear, con lo cual en el desarrollo del cigoto sólo intervendrán las mitocondrias contenidas en el óvulo. Sin embargo, actualmente se ha demostrado que las mitocondrias del espermatozoide pueden penetrar en el óvulo, pero no llegan a heredarse al ser marcadas por ubiquitinación y degradadas .[2]

Otra característica importante del ADN mitocondrial es que no se recombina. Ello implica que los únicos cambios que haya podido haber en el ADN mitocondrial se deben exclusivamente a mutaciones a lo largo de multitud de generaciones. Los cálculos estadísticos que se han realizado informan que, en los mamíferos y en concreto en el hombre, cada 10.000 años aproximadamente surge una mutación en una de las bases del ADN mitocondrial (esto no es del todo cierto, aunque sí lo es para el fragmento que más mutaciones sufre, que consta de unos 500 pares de bases). Es decir, la diferencia entre una mujer que hubiera nacido hace 40.000 años y un descendiente directo por vía materna que viviera en la actualidad sería por término medio de 4 bases. De hecho, un estudio realizado en los ADN mitocondriales de los europeos (Bryan Sykes) asegura que todos los europeos provienen de siete mujeres, las siete hijas de Eva. La más antigua habría vivido hace 45.000 años y la más moderna hace unos 15.000 años. La Eva mitocondrial, la antepasada común más moderna de todos las seres humanos que hay en el mundo, se remontaría de este modo a unos 150.000 años.

Referencias

1. ↑ Novo Villaverde, F.J. (2007). Genética Humana. Madrid: Pearson. ISBN 8483223598. (Recomendado)
2. ↑ Pakendorf, B. & Stoneking, M. (2005). "Mitochondrial DNA and human evolution". Annual Review of Genomics and Human Genetics 6: 165-83. PMID 16124858.[1] Nota: review muy recomendable para adquirir una visión general y bien referenciada acerca del genoma mitocondrial, su herencia matrilineal y su interés en estudios de genómica comparada.

Bibliografía recomendada

* "Las siete hijas de Eva" de Bryan Sykes.
* "El collar del Neandertal" de Juan Luis Arsuaga.

Tuesday, December 16, 2008

Searchers find remains of Teutonic Knights leaders

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Message: http://www.sacbee.com/836/story/1469213.html


Searchers find remains of Teutonic Knights leaders


By MONIKA SCISLOWSKA
Associated Press writer
Published: Friday, Dec. 12, 2008
WARSAW, Poland -- Polish archaeologists believe silk-draped skeletons found in a cathedral crypt are those of three grand masters who more than 600 years ago ruled the Teutonic Knights - an order that spread religion through force.

An archaeologist in the city of Kwidzyn - the Teutonic fortress of Marienwerder in the Middle Ages - said Friday that DNA tests indicate the remains are those of Werner von Orseln, the knights' leader from 1324-1330; Ludolf Koenig, who ruled from 1342-1345; and Heinrich von Plauen, who reigned from 1410-1413.

"Taking everything into account, we see that we are dealing with Teutonic Knights grand masters," Bogumil Wisniewski, an archaeologist who spearheaded the search, told The Associated Press. "We are 95, 96 percent sure it is them."

He said the skeletons, found in wooden coffins, were draped in silks - some painted with gold - a fabric reserved only to those highest in power in the Middle Ages.

DNA tests matched their age to that of the death age of the three grand masters. They also revealed temporary malnutrition in one of the skeletons that could match the 10-year imprisonment of von Plauen.

While Wisniewski acknowledged he could only be completely certain of the identities "if I met each face-to-face and he told me his name," he said several other indicators supported the find, including wall paintings in the cathedral showing the three grand masters and historic documents saying that von Orseln and Koenig were buried there. The order ruled in the area until early 16th century.

Wojciech Weryk, coordinator for city development and promotion, said the remains will be returned to the crypt and displayed under a special glass shield, so visitors can see them.

"This is such a valuable historic finding that we should show it," Weryk said.

The Order of the Teutonic Knights was founded in the late 12th century to aid German pilgrims in the Holy Land. It became a military order, wearing trademark white coats with black crosses, forcefully bringing Christianity to pagan Prussians. It took control along the Baltic Sea coast in what is now northern Poland.

The order was crushed by Polish and Lithuanian forces at the Battle of Grunwald in 1410.

Sunday, December 14, 2008

The mysteries of DNA

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Message: http://mormontimes.com/studies_doctrine/research_discoveries/?id=5363

In this 16-minute video presentation, Scott R. Woodward, executive director of Sorenson Molecular Genealogy Foundation, explains what DNA is, what it can teach us, what its weaknesses are and how it can be used to understand and track relationships between individuals and groups.

Woodward discusses the difference between the portions of DNA that are used to track groups and used to identify specific individuals. He explains the difference between using mitochondrial DNA, which tracks only the female line, and Y-Chromosome DNA, which tracks the male line.

Woodward tells how all of us have a real physical connection with other people on earth.

http://mormontimes.com/studies_doctrine/research_discoveries/?id=5363

Saturday, December 13, 2008

Nueva instrucción alienta investigación biomédica en respeto a dignidad humana y procreación

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Message: VATICANO, 12 Dic. 08 / 10:33 am (ACI).- Al presentar esta mañana en conferencia de prensa la instrucción "Dignitas personae": sobre algunas cuestiones de bioética, el Secretario de la Congregación para la Doctrina de la Fe, Mons. Luis Francisco Ladaria Ferrer, señaló que este documento "alienta a la investigación biomédica que respeta la dignidad de todos lo seres humanos y de la procreación".

Asimismo, el Arzobispo resaltó que la instrucción de 33 páginas presentada en inglés, francés, alemán, italiano, español, portugués y polaco, "excluye como éticamente ilícitas diversas tecnologías biomédicas y será probablemente acusado de contener demasiadas prohibiciones. Sin embargo, frente a esta posible acusación es necesario subrayar que la Iglesia siente el deber de hacer que se escuche la voz de los que carecen de ella".

Seguidamente Mons. Ladaria precisó que el documento es fruto de un estudio que emprendió en 2002 la Congregación para la Doctrina de la Fe sobre las nuevas cuestiones de bioética con el fin de actualizar la instrucción Donum vitae (1987) del mismo dicasterio. El documento, aprobado por el Papa, "forma parte del Magisterio ordinario del Sucesor de Pedro" y "es de naturaleza doctrinal".

Por su parte, el Presidente de la Pontificia Academia para la Vida, Mons. Rino Fisichella, señaló que la instrucción "trata de expresar la propia contribución autorizada en la formación de la conciencia no solo de los creyentes, sino de los que tratan de escuchar las argumentaciones que se presentan y debatirlas. Se trata de una intervención que forma parte de su misión y que debería ser escuchada no solo como legítima, sino también como debida en una sociedad pluralista, laica y democrática".

A su turno, Maria Luisa Di Pietro, Profesora asociada de Bioética de la Universidad Católica del Sagrado Corazón de Roma y Presidenta del la Asociación "Scienza e Vita", explicó que el documento considera "tres bienes fundamentales sobre los que se rige cada una de las decisiones" siendo el primero "el reconocimiento de la dignidad de persona a cada ser humano desde la concepción hasta la muerte natural, con la consiguiente subjetividad del derecho a la vida y a la integridad física"

El segundo y el tercero son "la unidad del matrimonio, que conlleva el respeto recíproco del derecho de los cónyuges de convertirse en padre y madre solo uno a través de otro; y "los valores específicamente humanos de la sexualidad, que exigen que la procreación de una persona humana sea querida como el fruto del acto conyugal específico del amor entre los esposos".

El Presidente Emérito de la Pontificia Academia para la Vida; Mons. Elio Sgreccia, habló luego sobre la tercera parte del documento en la que se habla de las nuevas propuestas terapéuticas que comportan la manipulación del embrión o del patrimonio genético humano.

"El texto resalta que es necesario tener en cuenta una distinción fundamental: la terapia genética teóricamente se puede aplicar a las células somáticas con finalidades directamente terapéuticas, o sobre las células germinales", indicó.

Por lo que respecta a estas últimas, "al no existir todavía una técnica segura, no es posible intervenir porque puede comportar el riesgo de malformaciones en el patrimonio genético hereditario, de las generaciones futuras", prosiguió.

Finalmente Mons. Sgreccia afirmó "que es insostenible la distinción entre clonación reproductiva y clonación terapéutica, porque también la llamada terapéutica presupone siempre una reproducción".

Para leer la síntesis del documento puede ingresar a: http://www.aciprensa.com/Docum/documento.php?id=216

Monday, December 08, 2008

New illness unique to French Canadian

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Message: Charlie Fidelman, Canwest News Service
Published: Thursday, December 04, 2008

MONTREAL - Canadian researchers have announced the discovery of a new illness called Mednik syndrome, a rare and debilitating genetic disorder unique to French Canadians.

So far only eight people have been identified with the mutation, and half of them died before age two, said neurologist Patrick Cossette of the University of Montreal Hospital Centre's Research Centre.

"It's a severe and debilitating illness," Cossette said, adding that the oldest patient with Mednik is now 15.

Mednik syndrome is attributed to common founders in the French Canadian population of Quebec who emigrated from France in between 1608 and 1759. Gene mutations in a small group such as Quebec's colonists could multiply easily.
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A research team led by Cossette discovered that the syndrome is caused by a newly found mutation in the AP1S1 gene. The gene is involved in the formation of the central nervous system and other organs.

"Our observations strongly suggest that Mednik syndrome is caused by impaired development of various neural networks, including the spinal chord, the inner ear, and possibly the brain," Cossette said. The finding was published Friday in the online version of Public Library of Science Journal PLoS Genetics.

The AP1S1 gene is responsible for transporting and sorting out proteins within the cells, Cossette explained.

Using genetic mapping and ascending genealogy, the mutation was traced to a group of families in Quebec from the Kamouraska region, in eastern Quebec, who share a common ancestor, Cossette said.

The mutation leads to severe mental retardation, red scaly skin patches, complete deafness, poor absorption of food in the gut and other problems.

Riviere-du-Loup dermatologist Christian Allen Drouin noticed several pediatric patients with skin lesions who also failed to develop normally, Cossette said.

The gene was mapped out at Genome Quebec, which promotes the research and development of genomics in the province. Two copies of the same recessive gene must be inherited to lead to the illness.

"Now that we know the gene, we can determine who is carrying it and avoid new cases of the syndrome," Cossette said, suggesting inhabitants of rural Kamouraska region be screened for the defect.

Researchers also knocked out the AP1S1 gene in zebra fish. In the animal model, the loss of the gene resulted in broad defects including severe motor deficits because the spinal cord was impaired, he said.

The discovery is expected to have implications beyond Mednik.

"It might be one piece of the puzzle in understanding deafness and mental retardation," Cossette said.

The disease is attributed to common founders in the French Canadian population of Quebec who emigrated from France in between 1608 and 1759.

Gene mutations in a small group such as Quebec's colonists could multiply easily.

Mednik is the latest of several "founder effect" disorders, including Tay-Sachs, identified among French Canadians.

Neuroscientists Eva and Fred Andermann of the Montreal Neurological Institute and Hospital, who were not involved in this study but have identified other recessive mutations in Quebec, said Cossette's discovery will be useful in identifying the mutation carriers.

"It's an interesting and unusual disorder," Fred Andermann said. "Advances in molecular biology has led to the identification of a lot of these disorders which were previously not recognized as entities, or were often mistaken as cerebral palsy or neonatal injuries."

SOURCE: http://www.canada.com/topics/bodyandhealth/story.html?id=1037068
© The Montreal Gazette 2008

Tuesday, November 04, 2008

Científicos clonan ratones congelados: ¿siguen los mamuts?

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Message: Científicos clonan ratones congelados: ¿siguen los mamuts?

http://www.jornada.unam.mx/ultimas/2008/11/04/cientificos-japoneses-logran-clonar-ratones-congelados-durante-16-anos/?searchterm=adn
http://www.jornada.unam.mx/ultimas/2008/11/04/cientificos-japoneses-logran-clonar-ratones-congelados-durante-16-anos/?searchterm=adn


Los investigadores japoneses sugieren que la técnica utilizada podría servir para "revivir" a especies extintas.

Dpa y Reuters
Publicado: 04/11/2008 13:06

Washington. Científicos japoneses lograron clonar ratones cuyos cuerpos estuvieron congelados durante 16 años. Los investigadores dijeron que podría ser posible utilizar la técnica para revivir a mamuts y a otras especies extintas.

El experto en clonación de ratones Teruhiko Wakayama y sus colegas, que trabajan para en el Centro para el Desarrollo Biológico, en el instituto de investigación RIKEN de Yokohama, Japón, consiguieron clonar a los pequeños mamíferos incluso cuando sus células se habían quemado por las bajas temperaturas.

El equipo de Wakayama utilizó la clásica técnica de transferencia nuclear para crear a sus ratones clonados. La técnica incluye extraer el núcleo de un óvulo y reemplazarlo con el núcleo de una célula común del animal a ser clonado.

Cuando se hace con el químico correcto o un detonador eléctrico, el proceso comienza a dividir el óvulo como si hubiese sido fertilizado con esperma.

"Clonar animales vía transferencia nuclear entrega la oportunidad de preservar a especies mamíferas en peligro", escribió el grupo en la revista Preceedings, de la Academia Nacional de Ciencias.

"Sin embargo, se ha sugerido que la resurrección de especies extintas que se encuentran congeladas (tales como el mamut peludo) es imposible, al no existir células vivas disponibles y que el material genético que está se encuentra inevitablemente degenerado", escribió el equipo científico.

Escarbando en el congelador

El grupo de Wakayama sacó algunos ratones que habían sido mantenidos congelados por años y cuyas células habían sido dañadas irremediablemente.

El congelamiento causa que las células se quemen y puede dañar el ADN en su interior. Unos químicos llamados crioprotectores pueden evitar esto, pero deben ser utilizados antes de que las células se congelen.

Los científicos intentaron esto utilizando células de diversos lugares y descubrieron que las del cerebro eran las que mejor funcionaban.

Esto resulta algo misterioso, ya que todavía nadie ha clonado un ratón vivo a partir de una neurona.

Los mamuts pueden ser los animales extintos que los científicos han intentado clonar con mayor entusiasmo, así como otros animales que se han encontrado congelados.

En julio de 2007, científicos rusos descubrieron el cuerpo de una cría de mamut congelada por cerca de 40 mil años en la región Yamalo-Nenetsk del Artico.

Dos familias españolas esperan el permiso para concebir embriones libres de cáncer

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Message: DIAGNÓSTICO GENÉTICO PREIMPLANTACIONAL
Dos familias españolas esperan el permiso para concebir embriones libres de cáncer

* La ley lo permite en 'enfermedades graves, de aparición precoz y sin tratamiento'
* La Comisión de Reproducción Asistida valorará los casos que no cumplan esos supuestos


Actualizado martes 04/11/2008 00:55 (CET)

http://www.elmundo.es/elmundosalud/2008/11/03/oncologia/1225713843.html


MARÍA VALERIO

MADRID.- Javier nació a mediados de octubre en Sevilla. Las células madre de su cordón umbilical servirán para curar a su hermano Andrés, que padece una enfermedad congénita, la beta talasemia mayor, de la que él mismo está libre gracias al diagnóstico genético preimplantacional. Pero, ¿qué ocurriría si sus genes llevasen impresa una predisposición a algún tipo de cáncer? ¿Es ético utilizar esta técnica para prevenir tumores hereditarios? Los oncólogos españoles lo han debatido recientemente y dos familias esperan una decisión.

Nadie duda de que el tema suscita aún importantes cuestiones éticas y legales. La técnica, autorizada en España desde hace años, permite analizar los preembriones concebidos mediante una fecundación 'in vitro' para ver si son portadores de determinadas alteraciones genéticas e implantar en el útero materno únicamente aquellos que están libres de dicha herencia.

En la actualidad, se calcula que un 5%-10% de todos los cánceres tienen carácter hereditario, es decir, son consecuencia de mutaciones germinales en ciertos genes que aumentan la susceptibilidad a enfermar en el futuro. En total, se conocen alrededor de 40 genes implicados en este tipo de síndromes hereditarios poco frecuentes, pero aunque la cuestión ha empezado ya a surgir en las consultas de consejo genético, no hay constancia de que el método se haya empleado aún en ningún centro público.

"Al menos en los síndromes más frecuentes, como el de mama y el de colon", según confirmó la doctora Ana Polo, del Hospital Sant Pau de Barcelona, en una jornada organizada recientemente en Madrid por la Sociedad Española de Oncología Médica (SEOM) y el Instituto Roche.

Joan Brunet, coordinador de la sección SEOM de Cáncer Hereditario y Consejo Genético, reconoce que desde hace siete u ocho años ha aumentado el número de parejas que acuden a las consultas con este dilema. "Se trata de gente sana, que sabe que es portadora de esta presdisposición, y que se encuentra en edad fértil", apunta a elmundo.es. Y de la misma manera que este diagnóstico preimplantacional ya se aplica desde hace años a otras enfermedades genéticas de manera rutinaria, ¿dónde está el límite para emplearlo en el caso de tumores?".
Tres condiciones

De hecho, Brunet no quiere dar ejemplos concretos y prefiere ceñirse a la ley 14/2006 que ha regulado más en detalle esta cuestión recientemente. Según el artículo 12 de este texto, el diagnóstico preimplantacional únicamente es legal para enfermedades graves, con muchas probabilidades de desarrollarse en los primeros años de vida, y con una alta tasa de mortalidad por falta de tratamientos. "¿Qué se entiende por grave? Algunos síndromes hereditarios entran claramente dentro de esta definición, pero ¿qué ocurre con una mujer joven, que quiere tener hijos y cuya madre, tía y hermana han muerto jóvenes por el cáncer de mama? Eso es lo que estamos intentando determinar con este tipo de debates", apunta.

Julio Martín, director del laboratorio de enfermedades del Instituto Valenciano de Infertilidad (IVI), prefiere hablar de 'neoplasias' en lugar de cáncer, y recuerda que existen muchos síndromes ("poco frecuentes") que se manifiestan con una proliferación celular irregular. "Como la neoplasia múltiple endocrina de tipo 2 A, un carcinoma de la glándula tiroidea, y que tiene una penetrancia del 95%, es decir, que las personas portadoras desarrollaban la enfermedad con mucha probabilidad", explica.

En este centro, se han realizado ya siete diagnósticos de esta enfermedad que han acabado en cuatro gestaciones. Igual que otros 14 diagnósticos de neurofibromatosis tipo 1 (que provoca la aparición de múltiples fibromas dérmicos, complicaciones óseas -displasia vertebral, escoliosis -, posibles malformaciones en la cara, y en un 50% de los casos, retraso en el aprendizaje), que han culminado en cinco embarazos, dos de ellos aún en curso.

En ambos ejemplos, se trata de patologías con un patrón hereditario dominante, es decir, que el riesgo de que los hijos de los afectados hereden la misma mutación que sus padres es del 50%. "Estas personas han visto la enfermedad en su familia, generación tras generación, y antes de disponer de esta posibilidad algunas de ellas incluso decidían no tener hijos".
Informe de la comisión

Según explican a elmundo.es fuentes del Ministerio de Sanidad, las comunidades autónomas están autorizando la técnica siempre que la solicitud cumpla las tres condiciones del artículo 12. Sólo en caso de duda solicitan el informe (favorable o desfavorable) de la Comisión Nacional de Reproducción Asistida, que debería evaluar caso por caso tras revisar la documentación pertinente (mutación, historia familiar...). Aunque por el momento, añaden, aún no han tenido que pronunciarse en ninguna solicitud de este tipo; probablemente porque los trámites todavía no han traspasado las 'fronteras' autonómicas.

"El departamento catalán de Salud tiene un grupo asesor que informa sobre la conveniencia o no de enviar la solicitud a la comisión nacional", añade por su parte Josep Maria Busquets, secretario del comité de Bioética de Cataluña (dependiente de la Generalitat). De manera que "este tipo de solicitudes [tipo BRCA] requieren la autorización del departamento de Salud, previo informe favorable de la Comisión Nacional de Reproducción Asistida". Busquets, añade que por el momento sólo se ha recibido una petición, "a la que se ha solicitado documentación complementaria".

Martín confirma que el IVI ha realizado dos consultas para las que aún espera respuesta. "Una, por un varón portador del gen BRCA1, que podía suponer para sus futuras hijas un mayor riesgo de cáncer de mama. La segunda, para una mujer con mutación en el gen BRCA2 y cuyo árbol genealógico mostraba una penetrancia de casi el 100%", explica. La razón para consultar estos casos y no el resto de síndromes neoplásicos, explica, es que nunca antes se ha utilizado en España el diagnóstico preimplantacional para cáncer de mama. "Los embriones portadores de la mutación no tienen porqué desarrollar la enfermedad en el futuro, de manera que nos vemos más respaldados solicitando este informe".

Las principales dudas (éticas y legales), coinciden todos los especialistas, surgen en el caso de familias con una fuerte penetrancia de los genes relacionados con algunos tumores de mama y de colon, que no se desarrollan hasta la edad adulta, y que no todos los portadores llegan a manifestar.

En general, los especialistas coinciden en que el uso de esta técnica para genes oncológicos debería estar sujeto a una serie de requisitos, "que pasan necesariamente por la consulta de consejo genético, la intervención de un equipo multidisciplinar, la valoración del riesgo de transmisión del tumor hereditario, la implementación de un estudio genético y el asesoramiento sobre medidas de detección precoz o prevención disponibles", según la nota de prensa de la SEOM sobre este foro de debate.

El uso del diagnóstico genético para casos de cáncer ya está aprobado en el Reino Unido desde 2006, aunque cada caso debe ser autorizado uno por uno, tras valorar la historia familiar, el tipo de mutación y otras circunstancias. En el caso español, el proceso sería el mismo, como explica Mónica Parriego, responsable del laboratorio de diagnóstico preimplantacional del USP Instituto Universitario Dexeus de Barcelona, donde aún no han tramitado ningún DGP relacionado con el cáncer.
Poco frecuentes

"Si la solicitud se saliese de los tres supuestos que marca la ley, la comisión debería evaluar cada caso y emitir un informe favorable o desfavorable", explica esta especialista a elmundo.es. "Aunque finalmente son las comunidades las encargadas de autorizarlo".

La técnica requiere extraer una o dos células del embrión cuando se encuentra en la fase de mórula (es decir, está formado aún por sólo de ocho a 12 células). Por cada célula se puede analizar una única patología, mientras que el resto del embrión sigue en cultivo a la espera de conocer el diagnóstico y pueda ser transferido a la madre. "No hacemos un 'barrido' a ver qué error encontramos, sino que estudiamos a la familia y acudimos exactamente a la mutación que causa la enfermedad en los progenitores", aclara Parriego. De hecho, la ley prohibe expresamente la selección positiva, es decir, la elección del embrión más fuerte, más inteligente, o el que tenga los ojos de un determinado color.

Brunet reconoce que es probable que algunas parejas se echen atrás después de informarse y conocer los riesgos y las limitaciones de la técnica. Por ejemplo, el tratamiento hormonal necesario para la reproducción asistida que puede aumentar el riesgo de cáncer de mama, los costes económicos, el tiempo, la burocracia o la probabilidad de que finalmente el embrión elegido no 'agarre' con éxito en el útero materno. "El debate es necesario", concluye, al tiempo que recuerda que la mayor parte de los tumores son de tipo esporádico y no hereditarios.

Friday, October 03, 2008

V REUNION INTERNACIONAL DE LOS ELIZONDO

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Message: V REUNION INTERNACIONAL DE LOS ELIZONDO
Octubre 10, 11 y 12 del 2008 en Monterrey, NL

PROGRAMA
Octubre 11 del 2008

9:30 a 10:00 Inscripciones de las Conferencias.

10:00 Ceremonia de Inauguración.
10:15 Presentación del Testamento del Cap. Francisco de Elizondo de Aguilar. por Profr. Miguel Ángel Muñoz Borrego.

10:45 Genealogía Molecular ADN
Benicio Samuel Sánchez García

11:15 Resumen del Testamento del
Cap. Francisco de Elizondo y Urdiñola.
Ing. Guillermo Garmendia Leal.


DESCANSO.
12:00 Exposición del Testamento del
General Pedro de Elizondo González.
Arq. José Francisco Garza Carrillo.
12:30 Conferencia sobre la Vida del
General Luis Alberto Guajardo Elizondo.
LAE. Luis López Elizondo.
COMIDA

15:30 a 17:30 Mesas Redondas

Octubre 10 del 2008 Bienvenida en el
17:00 a 19:00 Archivo General del Estado de Nuevo León.
Juan I. Ramón esq. Zaragoza
Macro Plaza de Monterrey

Octubre 11 del 2008. Conferencias en el
9:30 a 17:30 Auditorio de la Biblioteca Central
"Fray Servando Teresa de Mier"
Zuazua 655 Sur
Macro Plaza de Monterrey

Octubre 12 del 2008. Convivencia en el
9:30 a 15:00 Embarcadero del Paseo Santa Lucia
en Cintermex visita al Museo
Museo de Historia Mexicana visita a
Las Castas en la Nueva España

Monday, September 01, 2008

Reduce toronja mutaciones genéticas

This is an email from GenealogiaMolecular.com

Message: Reduce toronja mutaciones genéticas
Martes, 26 de Agosto de 2008
Grupo Reforma
Reforma
Ciudad de México

*Con el propósito de que el jugo conserve sus propiedades, se debe administrar a los ratones el líquido inmediatamente después de obtenerlo

Después de diez años de investigación, científicos del Instituto Politécnico Nacional (IPN) comprobaron que el jugo de toronja tiene efectos para reducir mutaciones en el ácido desoxirribonucleico (ADN) y lesiones precancerosas en el colon de modelos animales, lo que a futuro podría constituir una alternativa para prevenir este tipo de afecciones en humanos.

Se trata de un proyecto de investigación multidisciplinario único en México, que realiza el investigador de la Escuela Nacional de Ciencias Biológicas, Eduardo Madrigal Bujaidar, con el apoyo de los doctores en ciencias Isela Álvarez González, de la ENCB; y Javier Espinosa Aguirre, del Instituto de Investigaciones Biomédicas de la UNAM, destaca el IPN en un comunicado.

Madrigal indicó que después de practicar estudios meticulosos en ratones de la cepa NIH, los resultados han sido alentadores, por lo que se evaluarán en el mediano plazo los efectos del jugo de toronja en seres humanos, pues han comprobado que ese cítrico reduce entre 60 y 90 por ciento las alteraciones en el ADN y los lípidos oxidados.

Explicó que para desarrollar la investigación se administró a los animales un químico mutágeno, para provocar alteraciones en el ADN y favorecer el inicio de un proceso canceroso.

"Para evaluar la acción del agente mutágeno se extrae sangre a los ratones y se observa en el microscopio la cantidad de micronúcleos (fragmentos de cromosomas) presentes en las células, toda vez que son indicadores de las alteraciones que sufre el ADN; de forma paralela otros grupos de animales reciben el mutágeno y también jugo de toronja vía oral para analizar su efecto", puntualizó.

A su vez, Álvarez González indicó que con el propósito de que el jugo conserve sus propiedades, se debe administrar a los ratones el líquido inmediatamente después de obtenerlo.

"Para hacer este experimento se administra una sola vez el jugo y se evalúa su efecto cada 24 horas por cuatro días", afirmó.

La especialista refirió que la acción antioxidante del jugo de toronja reduce el daño de diversos agentes oxidantes sobre el ADN y con ello la posibilidad de desencadenar algún tipo de cáncer.

"El 80 por ciento de los cánceres tienen su origen en las alteraciones del ADN; la toronja podría inhibir la transformación de carcinógenos que requieren del citocromo p450 (enzimas metabolizadoras) para su activación", detalló.

Para evaluar la reducción de lesiones precancerosas en el colon, se administra el agente carcinogénico a cuatro grupos de ratones y a tres de ellos se le administró el jugo.

"Después de ocho semanas se efectuó la disección del intestino de los organismos, y se comprobó que existe una reducción aproximadamente del 50 por ciento de las criptas aberrantes (lesiones precancerosas) presentes en los animales a los que se administró el jugo", sostuvo.

Álvarez González subrayó que esta investigación ha permitido la generación de nuevos conocimientos en ciencia básica, así como la formación de seis alumnos de licenciatura, cuatro de maestría y tres de doctorado. La investigación ha sido publicada en dos revistas científicas internacionales.

Finalmente, Madrigal mencionó que la toronja tiene cualidades nutritivas y una actividad antimutagénica, por lo que es importante incluir su consumo en la dieta habitual.

"Pero es importante que no se consuma toronja cuando se está tomando algún medicamento, ya que puede haber reacciones que perjudiquen la salud", concluyó.

Source: http://www.presidencia.gob.mx/prensa/ultimasnoticias/?contenido=38162

Wednesday, August 20, 2008

El ADN de Jose Smith muestra que esta emparentado con los Reyes de Irlanda

This is an email from GenealogiaMolecular.com

Message: La investigación del DNA (o ADN) en la genealogía de José Smith Jr. ha dado de una sorpresa, según Ugo Perego, director de operaciones en Sorenson Molecular Genealogy Foundation: Un marcador raro del DNA demuestra que la presunción que la familia Smith
vino de Inglaterra es probablemente incorrecta.

Los Smith eran Irlandeses.

Perego hablo en 10ma Conferencia Anual de la Foundation for Apologetic Information & Research en el Centro de exposiciones South Towne en Sandy, Utah.
El resumió la investigación del DNA de José Smith Jr.

Se utilizó primariamente para investigar el DNA de José Smith Jr. el Cromosoma Y -es parte del DNA y se transmite únicamente en línea paterna-de padre a hijo y tiene pocas mutaciones.-

Elaine Nichols, especialista en la Genealogía de José Smith Jr, de acuerdo a Perego, escribió que la linea Smith puede ser seguida con seguridad hasta Robert Smith, quien posiblemente nació en 1626. Robert smith esta mostrado en 1638 en Boston Massachusets, como un sirviente por contrato limitado a un periodo de tiempo.
No se conocen padres ni hermanos.

Pensamos que seria bueno reconstruir la firma genetica de José smith Jr, la firma de la linea paterna, y luego, recolectar muestras de los Smith en Inglaterra, particularmente en el area de la que pensamos que Robert Smith procedia. Si pudieramos encontrar firmas genéticas similares, tendriamos el puente entre los Smith Mormones o de Utah, y aquellos de Inglaterra, y encontrar la forma de vincular usando DNA, dijo Perego.


Usando muestras genéticas de varios descendintes conocidos de José Smith Jr y de su padre, ejemplares seguros de su Cromosoma Y, permitió que su perfil genético fuera identificado. Así no se necesitó ninguna muestra de huesos, ni sangre, ni cabello.

"Si José Smith estuviera frente a mí y fuera posible tomar una muestra de sus células, y tomar así su DNA, no tendría ninguna información adicional o nueva a la que ya tenemos mediante las muestras de sus descendientes. Así de segura es la informacion genética que tenemos."

Teniendo este perfil genético de su DNA, es posible analizar a quienes alegan ser descendientes de él.

Perego mostró una lista de personas que afirman ser descendientes de José Smith Jr. EL DNA de algunos ha sido analizado y comparado.

Por ejemplo: Moroni Pratt no es su hijo, contrariamente a lo que Fawn Brodie especuló en su biografia critica de José Smith Jr. llamada: "No Man Knows My History".

Zebulon Jacobs, tampoco es su hijo.

Oliver Norman Buell fue declarado por Brodie ser hijo de José Smith Jr. ella comparó su fotografía con José Smith III. "Aún el estilo del peinado es el mismo", -Perego obtuvo algunas risas de la audiencia-, pero a pesar de las similitudes físicas, Buell no es hijo de Smith Jr.

Mosíah L. Hancock no era su hijo tampoco.

Con el uso de otras pruebas de DNA o ADN, Perego espera también determinar si Josephine Rosetta Lyon es una hija de Joséph Smith. Hasta la fecha se ha recolectado 120 muestras de ADN de sus descendientes. Él dice que deberá saberse en el "año que viene más o menos. (2009)"

Mi testimonio de José Smith no tiene absolutamente nada que ver con hasta qué punto él practicó la poligamia", dijo Perego. "Pero hay una interesante situación en la que hay literalmente miles de personas descendientes de esas personas que se preguntan, sobre la base de lo que se ha escrito, sean o no descendientes de Joséph Smith, y así que aquí tiene la oportunidad de decirle a estos la gente cómo están las cosas. "

Si José Smith engendró algunos de los otros niños en la lista nunca podrá ser conocido, porque algunos de ellos murieron demasiado jóvenes para tener sus propios niños. "No estoy realmente en el negocio de rondar y la excavar tumbas y realizar las pruebas", dijo Perego.


Perego luego regresó a su búsqueda del antepasado de Joséph Smith en Inglaterra. Debido que el último ancestro determinado en la línea paterna Smith, Robert Smith, fue sirviente por contrato de un hombre que tenía una propiedad en Kirton, Lincolnshire, Inglaterra, la hipótesis que se hizo fue que Robert Smith también era de Kirton.

Otro Robert Smith fue encontrado allí y había tenido un hijo llamado Robert aproximadamente al tiempo correcto del calculo genealógico.

Este nuevo Robert Smith se supone fue el padre de sirviente Robert Smith que llegó a América - aún cuando la relación es débil.

Smith es un apellido común, por supuesto, y Robert es el más popular primer nombre al momento.

Aquí es donde la ruta de investigacion va completamente en frío utilizando los métodos estándar o tradicionales de genealogía.

El objetivo de Perego es ver si cualquier traza del ADN de la familia Smith se encontraban todavía en la zona. Si Robert Smith había venido de esa zona, algun vestigio de ADN debe permanecer allí. Esto añadiría algún apoyo para el registro genealógico.

Perego escribió cartas a los 1,100 Smith del área de Lincolnshire pidiendo muestras de ADN. Treinta y tres personas respondieron, pero las pruebas mostraron cero parecido con el ADN de José Smith.


El ADN de José Smith es raro para esos Smith - incluso entre los Smith en los Estados Unidos.

Sin ningún éxito en el objetivo, Perego amplió la red - utilizando tanto áreas específicas del ADN del cromosoma Y de José Smith, como su perfil de "haplogrupo" para buscar coincidencias.

Un haplogrupo es una agrupación de perfiles de cromosoma Y que comparten características similares.

Estos haplogrupos son habitualmente "geográficamente específicos".


En primer lugar, Perego puso el perfil de ADN de Joséph Smith en la base de datos de Sorenson Molecular Genealogy Foundation de 23,403 muestras de cromosoma Y. Fue en busca de matches o similares al momento en que Robert Smith llegó a América.

Él encontró coincidencias, muchos de los cuales son Irlandeses (irish o gaélico).

A partir de ahí, Perego identifico una parte del ADN de Joséph Smith y observó un marcador muy raro llamado M222. Con una "resolución más alta" encontró que el mismo marcador fue encontrado en el noroeste de Irlanda - y unos poco encontrados en las tierras bajas de Escocia.

Por último, Perego analizo un estudio publicado en 2006 de esta misma zona de Irlanda.

Un perfil del cromosoma Y se ha encontrado que se atribuye a los muchos descendientes de "Niall of the Nine Hostages," un señor del siglo V que fue el antepasado de los reyes de Irlanda hasta el siglo X.

Perego compararó el cromosoma Y de Joséph Smith Jr y descubrió que se corresponde muy de cerca.

Esta es otra indicación de que los antepasados de Smith a lo largo de su línea paterna eran no sólo de Irlanda, sino que probablemente relacionados con la Nobleza Irlandesa.


"Quizás este sierviente, de 12 años de edad, era un descendiente de Irlandés, quizás sólo una o dos generaciones antes ellos vivieron en Irlanda ... y se trasladó a Inglaterra," dijo Perego. "El Pueblo irlandés no fue muy bien visto en Inglaterra, tal vez hubo un cambio de apellido. Smith tal vez no era un Smith, fue otro apellido en algún momento."

Perego especuló que los Smith irlandeses probablemente no vivieron en Inglaterra por muchas generaciones, de lo contrario se habría encontrado una gran cantidad de parecidos genéticos en las muestras se obtuvieron de los Smith Ingleses que viven ahora en esa área.

"Espero que esto no cambia el testimonio de nadie aquí", bromeó. "Me siento bien sobre el pueblo irlandés."


E-mail: mdegroote@desnews.com

MormonTimes.com is produced by the Deseret News in Salt Lake City, Utah.
It is not an official publication of The Church of Jesus Christ of Latter-day Saints.
Copyright © 2008 Deseret News Publishing Company

Saturday, August 09, 2008

DNA shows Joseph Smith was Irish

This is an email from GenealogiaMolecular.com

Message: DNA shows Joseph Smith was Irish
By Michael De Groote
Mormon Times
Published: Friday, Aug. 8, 2008

SANDY, Utah -- DNA research into Joseph Smith Jr.'s genealogy has turned up a surprise, according to Ugo Perego, director of operations at the Sorenson Molecular Genealogy Foundation: A rare DNA marker shows that the assumption Smith's family line came from England is probably wrong.

The Smiths were Irish.

Perego was speaking at the 10th annual Mormon Apologetics Conference presented by the Foundation for Apologetic Information & Research this week at the South Towne Exposition Center in Sandy. He recounted the investigation into Joseph Smith's DNA and some of the results.

The primary means used to investigate Joseph Smith's DNA was the Y chromosome -- a part of DNA that is only passed from father to son and has few mutations.

Elaine Nichols, a specialist in Joseph Smith's genealogy, according to Perego wrote in 1991 that Smith's line can only be followed with confidence back to Robert Smith, possibly born in 1626. Robert Smith showed up in 1638 in Boston, Mass., as an indentured servant to another man. No parents known. No siblings known.

"At that time we thought: 'Wouldn't it be cool if we can reconstruct the Joseph Smith genetic signature, the paternal-line signature ... and then, somehow,... collect samples from Smiths in England, particularly in the area where we think (Robert Smith) came from, see if we find similar genetic signatures there, and perhaps bridge the gap between the Utah or Mormon Smiths and those in England -- and find a way to bridge this genealogical gap using DNA,'" Perego said.

By using DNA samples from several known Joseph Smith Jr. and his father's descendants, an accurate example of his Y chromosome DNA profile was identified. There was no need to test his blood or bones or hair or anything.

"If I had Joseph Smith standing by me and be able to (take a sample of his cells) and get some DNA from him, I wouldn't know any additional information than what I already know based on the (samples) of his descendants. That is how accurate this information is," Perego said.

Having this accurate DNA profile also enabled testing of his alleged descendants through polygamous or plural wives.

Perego showed part of a list of alleged children of Joseph Smith through other wives. The DNA of a number of the alleged children was identified and compared:

Moroni Pratt was not his child, contrary to what Fawn Brodie speculated in her critical biography of Joseph Smith, "No Man Knows My History."

Zebulon Jacobs was not his child.

Oliver Norman Buell was claimed by Brodie to be a son of Joseph Smith. She had compared his photograph with Joseph Smith III. "Even the hairstyle was the same," Perego said, eliciting some laughter from the crowd. But notwithstanding the physical similarities, Buell was not Smith's child.

Mosiah L. Hancock was not his child either.

Using other DNA tests, Perego also hopes to determine whether Josephine Rosetta Lyon is a daughter of Joseph Smith. So far he has collected 120 DNA samples from her descendants. He says they should know in the "next year or so."

"My testimony of Joseph Smith has absolutely nothing to do with to what extent he practiced polygamy," Perego said. "But there is an interesting situation in which there are literally thousands of people descended of these individuals that are wondering, based on what has been written, whether or not they are descendants of Joseph Smith, and so here you have a chance to tell these people how things are."

Whether Joseph fathered some of the other children on the list may never be known, because some of them died too young to have any children themselves. "I'm not really in the business of going around and digging up graves and testing," Perego said.

Perego then returned to his search for Joseph Smith's ancestor in England. Because Joseph Smith's last certain ancestor on the Smith paternal line, Robert Smith, was indentured to a man who had property in Kirton, Lincolnshire, England, the assumption was made that Robert Smith was also from Kirton.

Another Robert Smith was found there who had a son named Robert at about the correct time. This new Robert Smith was assumed to be the father of the younger indentured servant Robert Smith who came to America -- even though the connection was weak. Smith is a common name, of course, and Robert was the most popular first name at the time.

This is where the trail goes completely cold using standard genealogical methods. Perego's goal was to see if any traces of the Smith family DNA were still in the area. If Robert Smith came from that area, some matching DNA should remain in living Smiths. This would add some support to the genealogical record.

Perego wrote letters to 1,100 Smiths in the Lincolnshire area asking for DNA samples. Thirty-three people responded, but testing showed zero matches with Joseph Smith's DNA.

The Joseph Smith DNA was unusual for Smiths -- even among Smiths in the United States.

Without any success in the target area, Perego cast a wider net -- using both Joseph Smith's specific DNA Y chromosome profile and a "haplogroup" to look for matches. A haplogroup is a grouping of Y chromosome profiles that share similar characteristics. These haplogroups are usually very geographically specific.

First, Perego put the Joseph Smith DNA profile into the Sorenson Molecular Genealogy Foundation database of 23,403 Y chromosome DNA samples. He was looking for matches from about the time when Robert Smith came to America. He found close matches, many of which were Irish.

From there, Perego identified a part of Joseph Smith's DNA that had a very rare marker called M222. With this "higher resolution" he found that the same marker was found in Northwest Ireland -- with a little bit in Lowland Scotland.

Finally, Perego looked at a study published in 2006 that dealt with this same area of Ireland. A Y chromosome profile had been found that was attributed to the many descendants of "Niall of the Nine Hostages," a fifth-century Irish warlord who was the ancestor of the kings of Ireland up to the 10th century. Perego compared that Y chromosome with Joseph Smith's profile and found they matched very closely. This was another indication that Smith's ancestors along his paternal line were not just Irish, but probably related to Irish royalty.

"Perhaps this indentured servant, this 12-year-old boy, was an Irish descendent, perhaps only one or two generations before they were living in Ireland ... and moved to England," Perego said. "Irish people were not viewed too well in England, perhaps there was a surname change. Perhaps Smith was not a Smith, was something else at some point."

Perego speculated the Irish Smiths were likely not in England for many generations, otherwise he would have found a lot of genetic matches from the samples he collected from the English Smiths who live now in that area.

"I hope that that doesn't change anybody's testimony here," he joked. "I feel OK about the Irish people."


--------------------------------------------------------------------------------

E-mail: mdegroote@desnews.com


MormonTimes.com is produced by the Deseret News in Salt Lake City, Utah.
It is not an official publication of The Church of Jesus Christ of Latter-day Saints.

Copyright © 2008 Deseret News Publishing Company

Thursday, July 24, 2008

¿Qué es la genealogía por ADN?

This is an email from GenealogiaMolecular.com

Message: ¿Qué es la genealogía por ADN?
¿Quiénes fueron nuestros antepasados? ¿De dónde provenimos? La mayoría de los hombres pueden rastrear su árbol genealógico como máximo tres o cuatro generaciones atrás. Pero gracias al análisis genotípico una mirada hacia milenios largamente olvidados es posible.

La historia de nuestros ancestros es una de las más fascinantes de todos los tiempos. Es la historia de la humanidad. Durante siglos, los huesos y objetos que nuestros antepasados dejaron en su camino proporcionaban los únicos puntos de apoyo para antropólogos y arqueólogos. De esa manera, las distintas teorías evolutivas no podían ser efectivamente probadas. Recién durante los últimos 20 años los investigadores descubrieron en el ADN de hombres vivos pruebas de las migraciones de sus ancestros.

El ADN es idéntico en un 99,9 por ciento en todos los hombres. El 0,1% restante es la causa de las diferencias individuales (p. ej. color de ojos, riesgos de determinadas enfermedades o anormalidades sin una función aparente). Puede ocurrir en estos segmentos carentes de función del ADN una alteración casual e inocua del ADN (mutación) que habrá de reiterarse en todos los descendientes de la persona en cuestión. Si la misma mutación aparece generaciones después en el ADN de dos personas, resulta claro que estas tienen un antepasado en común. La comparación determinados segmentos de ADN (marcadores genéticos) en muchas comunidades poblacionales distintas posibilita que se rastreen lazos de parentesco.

La mayor parte del genotipo se entremezcla una y otra vez por la combinación del ADN de padre y madre. En dos regiones del genotipo, sin embargo, esto no es el caso:
En el ADN mitocondrial (ADNmt): El ADNmt se hereda intacto de la madre al niño. Cada persona – indiferentemente de que sea varón o mujer – hereda su ADNmt exclusivamente de su madre.
En el cromosoma-Y: El cromosoma-Y se transmite sin modificaciones del padre al hijo. Cada varón recibe su cromosoma-Y exclusivamente de su padre.
Una comparación del ADNmt y el cromosoma-Y en personas de distintos estratos demográficos brinda a los genetistas una idea de cuándo y cómo se separaron estos grupos en las migraciones alrededor de la tierra. Si se comparan por ejemplo los cromosomas-Y entre europeos y aborígenes australianos, se encuentran diferencias características: los aborígenes varones llevan frecuentemente un cromosoma-Y con un patrón bien determinado en un lugar del ADN. Este marcador con la denominación M130 no se encuentra en europeos, aunque sí se encuentra muy frecuentemente uno de nombre M89, que no se da entre los aborígenes. El marcador M168, en cambio, se encuentra en los dos grupos. Evidentemente hubo entonces un antepasado común masculino a los europeos y aborígenes del que proviene el marcador 168. Sus descendientes sin embargo tomaron caminos separados en algún momento: unos se asentaron en el sudeste asiático y Australia, los otros llegaron con el correr del tiempo a Europa. Una vez que el contacto entre ambos grupos llegó a su fin, se presentaron nuevamente mutaciones casuales que se heredaron de generación a generación y hoy pueden registrarse en sólo una de las dos poblaciones.

Entre el Primer hombre originario y el hombre moderno actual yacen siglos de lucha por la supervivencia, de migraciones, de aislamiento y conquista. La mayoría de los detalles son desconocidos hasta ahora. Lo seguro es que estos hombres colonizarón el mundo entero. ¿Qué los motivó a emigrar?


Madre primigenia Eva, Padre primigenio Adán

Los investigadores parten hoy del supuesto de que todos los seres humanos están emparentados con una única mujer: con la "Eva mitocondrial". Pero el análisis de nuestros genes indica que la humanidad entera desciende de esta mujer a través de una cadena ininterrumpida de madres. Análogamente a la Eva mitocondrial, Existe el "Adán del cromosoma-Y", el padre originario de todos nosotros.

Los errores de copiado hacen la diferencia
Cada una de las células de nuestro cuerpo contiene una copia de nuestro ADN. Siempre que una célula se divide, debe copiar su ADN para que cada célula hija obtenga el ADN completo. Este proceso funciona con gran precisión. Sin embargo, el proceso no es perfecto. Si por ejemplo el ADNmt se copia y almacena en una cigota, la secuencia de nucleótidos mitocondriales en el huevo casi siempre se corresponde con aquella de las otras células de la madre. Ocasionalmente empero ocurre un error. Una piedra angular del ADN (nucleótido) se permuta, y en lugar de una A se encuentra quizá una G. A cada error de este tipo en la replicación del ADN se lo denomina una mutación.

Tales mutaciones son la clave para la reconstrucción de nuestra historia genética. Supongamos que la Eva mitocondrial haya tenido dos hijas, de las cuales una casualmente presentó una única mutación en su ADN mitocondrial. Todas las mujeres vivas hoy en día que descendieran de esta hija presentarían dicha mutación, mientras que todas las mujeres que descendieran de la otra hija no la llevarían consigo. La Eva mitocondrial habría dado origen por lo tanto a dos líneas mitocondriales de descendencia (haplogrupos). Las dos secuencias diferentes de ADN mitocondrial se denominan haplotipos.

Los haplotipos y haplogrupos son como árboles genealógicos que le permiten a los genetistas conocer quién está emparentado con quién. El anillo de ADN contenido en las mitocondrias es tan pequeño que raramente ocurren mutaciones. Las secuencias de ADN de nuestros cromosomas son 40.000 veces más largas que las de nuestras mitocondrias.

Cuando los hombres se vuelven adultos, las mutaciones que heredaron de sus padres se reproducen en su semen u ovarios, junto con otras mutaciones que conforman la singularidad de la generación siguiente. Cada generación deja así su sello sobre el ADN que ha heredado a través de nuevas mutaciones. El resultado es una compleja genealogía, un intrincado y ramificado árbol genealógico de alteraciones genéticas.

Haplogrupos-Y en España

This is an email from GenealogiaMolecular.com

Message: Haplogrupos-Y en Espana

R1B 76 %
E1B1B 15 %
R1A 9 %

--------------------------------------------------------------------------------

¿Qué son los haplogrupos?

Los haplogrupos pueden considerarse como las grandes ramas del árbol genealógico del Hombre. Estas ramas que son los haplogrupos muestran cómo diversas poblaciones se desplazaron sobre la tierra. Así, los haplogrupos también definen una región geográfica.

Monday, July 21, 2008

GeneTree.com añade la opcion del Analisis de Coromosma Y para Genealogia

This is an email from GenealogiaMolecular.com

Message: Amigos,

Como saben luedo de tener los resultados de ADN tanto mitocondriales como del Cromosoma Y es necesario calcular el Haplogrupo a fin de localizar personas que comparten ancestros de forma más cercana con nosotros que los de haplogrupos distintos al nuestros.

GeneTree nos pfrece ese servicio gratuito para el ADN Mitodondrial y si ya tienes tus resultados del Cromosoma Y, agregalos y podras localizar parientes.

La noticia original se anexa abajo, cualquier duda estamos a tus órdenes

***********************************^^^^^^************************************************


GeneTree Adds Y-Chromosome DNA Testing Option to Trace Paternal Line Ancestors, Research Surnames and Connect with Present Day Relatives

Addition of New Test Means GeneTree Participants Can Now Conveniently Tap into the World's Largest and Most Diverse Databases of Linked DNA and Family History Information Using Both Y-Chromosome (Paternal Line) DNA and Mitochondrial (Maternal Line) DNA Profiles.

Last update: 7:31 a.m. EDT July 21, 2008

SALT LAKE CITY, Jul 21, 2008 (BUSINESS WIRE) -- GeneTree, a DNA-enabled family history-sharing networking Web site designed to help people understand where their personal histories belong within the greater human genetic story, today added a Y-chromosome DNA testing option allowing participants to search for paternal line ancestors in the world's largest and most diverse genetic genealogy databases. Providing a Y-DNA testing service along with its existing mitochondrial DNA testing means GeneTree participants can now conveniently research both paternal and maternal lineages using DNA profiles.
"This is a powerful addition for people exploring their genealogy through genetics," said Matt Cupal, GeneTree COO. "Researching a paternal line with Y-DNA enables a person to go deep into their ancestry beyond traditional research roadblocks, such as missing documentation. Also, it can help them understand how a living person with the same last name is related to them."
Y-DNA is an unrivaled tool for tracing paternal ancestry. Only males have the Y-chromosome, which is passed down from father to son, and males with a common paternal ancestor have almost identical Y-DNA. Women may trace their paternal line by arranging Y-DNA testing for their father, a brother or other male relative in their direct paternal line. Because people generally inherit their surnames from their father, Y-DNA testing is an excellent tool for surname research.
Launched in October 2007, GeneTree applies social networking and rich media technologies to genetic genealogy providing individuals with innovative tools to map, assemble, record and share their family histories. Participants collaborate to build family networks online and add new connections with previously unknown living relatives. GeneTree is working in partnership with the Sorenson Molecular Genealogy Foundation in building the world's most comprehensive genetic genealogy databases with the intention of expanding the concept of family and deepening the ability of individuals to comprehend their place within the human family.
The GeneTree.com online pressroom is located at www.genetree.com/help/pressroom.html, and provides high-resolution images, FAQs, backgrounder and product brochure.
Pricing and Availability
Beginning immediately, GeneTree is offering two Y-chromosome DNA test options: a basic 33-marker test and an enhanced 46-marker test. Prices begin at $149 with discounts for those who have already had a mitochondrial DNA test through GeneTree. Additional information is available at www.genetree.com.
About GeneTree
GeneTree ( www.genetree.com) is a DNA-enabled family history-sharing Web site designed to help people understand where their personal histories belong within the greater human genetic story. GeneTree creates opportunities for unlocking human genetic heritage, discovering ancestors, connecting and collaborating with living relatives, and sharing rich media to help discover, document and preserve family histories. GeneTree was developed by the Sorenson family of companies and draws on the expertise of the Sorenson Molecular Genealogy Foundation, a nonprofit organization that developed the world's foremost collection of genetic-genealogy information; Sorenson Media, which created the world's leading digital video compression software; and Sorenson Genomics, which pioneered Internet-based consumer DNA testing.
SOURCE: GeneTree
GeneTree Public Relations
Jacob Moon, 801-520-2960
jacob@sorensoncompanies.com

Saturday, July 19, 2008

Mormon Physicians Pioneer Research in Genetics

This is an email from GenealogiaMolecular.com

Message: Mormon Physicians Pioneer Research in Genetics

18 July 2008 A humble, unassuming pair of Mormon physicians, Dr. Homer R. Warner, 86, and Dr. James O. Mason, 78, recently reminisced over the early days of their respective medical careers. Both doctors, nationally recognized and acclaimed, found themselves on the cutting edge of medical research in the 1950s, 60s and 70s.

Warner expanded his Ph.D. research in heart studies with the development of an analog computer circuit and eventually pioneered medical informatics — the diagnosis and recording of patient symptoms utilizing a main frame computer. In a science that seems routine to current physicians, Warner blazed an important path for patient care as well as medical research. "You do a series of little things that seem not that important or even connected, and then something jumps out at you," Warner said as he explained his initial body of research. "You learn to take the opportunity and look at things in a whole new way."

Mason, who encountered many? of Warner's new techniques in the 1960s during training in Boston, returned to Utah to collaborate with Warner on the staff at LDS Hospital in Salt Lake City. Subsequently named executive director of the Utah State Health Department, Mason facilitated an agreement between that hospital, the University of Utah, The Church of Jesus Christ of Latter-day Saints and the state health department to establish the Utah Population Data Base (UPDB). The UPDB consists of Church family history records, vital statistics from the state health department and other state government agencies, and medical records from the University of Utah and Intermountain Health Care hospital systems.

"It was a visionary move by the Church to share those genealogical records with the medical community," Mason explained. "They had been submitted for an entirely different purpose and it was a leap of faith on the part of (senior Church leaders) to release the records for research, to protect the Church's privacy and yet advance the causes of medical science."

Medical genetics research, sometimes facilitated by Warner's efforts, was also greatly enhanced by the individual efforts of two other groundbreaking Latter-day Saint physicians, Dr. Charles Smart and Dr. Roger Williams, both now deceased. Dr. Smart, in 1966, established the Utah Cancer Registry, a reported record of every diagnosed case of cancer in the state. Williams defined similar data bases for individuals with heart diseases.

Based on these timely collections of medical information and the genealogical records, other University of Utah and medical personnel were able to indentify genetic links to cancers, heart diseases and other inherited illnesses.

"The application of these contributions is huge; this genetics research couldn't occur without access to these family histories," Mason noted. "I've heard President (Gordon B.) Hinckley say that 'the Lord has more than one purpose in mind for family history.'"

Source: http://www.newsroom.lds.org/ldsnewsroom/eng/search/mormon-physicians-pioneer-research-in-genetics

Saturday, July 12, 2008

¿Donde consulto mi resultado de ADN para Genealogia?

This is an email from GenealogiaMolecular.com

Message: ¿Donde consulto mi resultado?
La base de datos esta en la pagina de la Sorenson Molecular Genealogy Foundation.

Los hombres deben consultarla en la Base de Datos del Cromosoma Y.

Las mujeres que participan deben consultarla en la Base de Datos de ADN Mitocondrial.

Si no puedes ver los links:
Hombres:

http://www.smgf.org/ychromosome/search.jspx
Mujeres: http://www.smgf.org/mtdna/search.jspx

Paso 1:

Despues de realizar la Prueba de ADN usando el GenetiRinse esperar a que los resultados se publiquen en www.smgf.org

Hombres:
- buscar en el caso de los hombres por apellido del primer ancestro fallecido en linea paterna, el tiempo promedio de espera es de 6 meses.

http://www.smgf.org/ychromosome/search.jspx

a.. Select DNA Testing Company: Relative Genetics
b.. Search By Surname: Escribe los apellidos (si en tu PAF escribiste 2 apellidos escribelos en la busqueda)


Mujeres:
- buscar en el caso de las mujeres por apellido del primer ancestro fallecido en linea materna, el tiempo promedio de espera es de 16 meses.

http://www.smgf.org/mtdna/search.jspx

a.. Select DNA Testing Company: Relative Genetics
b.. Search By Surname: Escribe los apellidos (si en tu PAF escribiste 2 apellidos escribelos en la busqueda)


Paso 2: (Para Hombres)
* Ya que localizaste tu informacion deberas corregir los valores erroneos en tu busqueda (cuadritos oscuros), toma nota de cual
> marca esta oscuro y el valor que tiene, regresa (realiza una
> nueva busqueda Y ABAJO DE DONDE ESCRIBISTE EL APELLIDO cambia los valores
> que estan escritos, yo escojo el standar de Relative Genetics y me salen
> pocos cuadritos oscuro) corrigiendo cada cuadrito oscuro,


.

Paso 2: (para Mujeres)


Ya que localizaste tu informacion deberas corregir los valores


> erroneos en tu busqueda (cuadritos oscuros), toma nota de cual
> marca esta oscuro y el valor que tiene en tu caso solo hay 4 opciones A,C,G,T, regresa (realiza una
> nueva busqueda Y ABAJO DE DONDE ESCRIBISTE EL APELLIDO cambia los valores
> que estan escritos, yo escojo el standar de Relative Genetics y me salen
> pocos cuadritos oscuro) corrigiendo cada cuadrito oscuro,
> Paso 3:
> * Una vez que ya tienes todos tus cuadritos en azul claro (PARA LOS HOMBRES) y ROsa para las mujeres


(excepto los cuadritos en blanco, ya no se dispone de informacion de ellos), realiza:

> una busqueda por Search By Match (%): asi apareceran los que
> comparten un ancestro en comun contigo.
> *Tambien hazlo en www.ysearch.org y de ser posible registrate alli y pon en
> linea tu arbol genealogico usando un gedcom
> Paso 4: Solo para Hombres
> * Seria bueno calcular tu haplogrupo, usando los valores de tu ADN
> (cuadritos azul claro) visita
> https://home.comcast.net/~hapest5/hapest5a/hapest5.htm?order=num

> y escribe los valores de cada marca, notaras que ha medida que los
> registras te indica un porcentaje, una vez que termines de registrar
> todos tus valores tendras calculado tu haplogrupo.
> Paso 5: Solo Hombres
> * Localiza en una busqueda en www.google.com del mapa escribe algo
> como: R1b map o segun corresponda. (R1b es mi haplogrupo, creo que
> bastante comun)
> Tambien puedes hacer esta busqueda en www.smgf.org y www.ysearch.org

Tuesday, July 08, 2008

Los Varones comparten ancestros: aprende como calcular el a��o de entroncamiento

This is an email from GenealogiaMolecular.com

Message: .

TMRCA: Compartimos Ancestros


Con el Y-DNA, podemos definir el número de generaciones que hay a un antepasado en común (TMRCA) , éste sería el antepasado paterno directo más cercano que dos varones tienen en común (tal como un abuelo o un bisabuelo remoto).

En general, cuanto más coincidencias en haplotipos entre individuos, más corto es el tiempo a un antepasado en común.

Por ejemplo, si dos individuos comparten 35 de 36 marcadores, comparten a un antepasado en común más reciente que dos individuos que compartan 32 de 36 marcadores.

Calcular el tiempo al antepasado en común más reciente se basa en probabilidad y no es una ciencia exacta. Podemos calcular el tiempo más probable que un antepasado en común pudo haber vivido, pero habrá siempre un grado de incertidumbre.

Por esta razón, es mejor que piense en TMRCA como un rango de tiempo más bien que un punto exacto en el tiempo.

Si Usted ya tiene sus resultados de Cromosoma Y, ya sea de usted o de algun hormano o su padre puede calcular el año probable de entroncamiento con otra persona.

Descargue la herramienta (archivo excel) AQUI

Nota: si deseas puedes descargarla de:
http://www.genealogiamolecular.com/herramientas/tmrca.xls

Coloca tus valores del cromosoma Y en Profile 1
coloca los valores de la otra persona (debe ser los valores del cromosoma Y) en Profile 2

Veras que en la parte inferior izquierda se va mostrando el año probable de entroncamiento.

Busca personas que entronquen contigo en un rango de 500 años ya que asi existe una posibilidad de poder localizar documentalmente el entronque.

Wednesday, July 02, 2008

The Science of Molecular Genealogy

This is an email from GenealogiaMolecular.com

Message: The Science of Molecular Genealogy
By Ugo A. Perego; Ann Turner, M.D.;
Jayne E. Ekins; and Scott R. Woodward, Ph.D.
Molecular science can help genealogists uncover previously unknown family relationships,
verify or refute claims to ancestry, and shed light on questions that have puzzled
family historians for years.
All individuals carry a record of their ancestors in a complex chemical
compound found inside almost every cell. Analysis of this molecule—
deoxyribonucleic acid (DNA)—can help genealogists trace male- and
female-line ancestors, prove and disprove relationships, reveal undocumented
illegitimacies and adoptions, and identify familial ethnic and geographic origins.
DNA is packaged in threadlike structures called "chromosomes." Humans
receive twenty-three chromosomes from each parent and, in turn, give half of
their own DNA to each of their children. Parents, therefore, funnel a molecular
record of their ancestors to their descendants.
More than 99 percent of each person's DNA is identical to that of all other
people. This shared inheritance defines humans, yet the remaining 1 percent
contains enough variation to make each person unique. The DNA of two closely
related people has more similarities than that of distant cousins. Consequently,
similarities and differences in DNA can show how closely individuals are related.
Molecular genealogists—also called "genetic genealogists"—test DNA
samples from living individuals. Used in isolation, DNA test results have little
value for family historians. Combined with documentary genealogical research,
however, DNA evidence can help researchers identify ancestors and reconstruct
family histories and lineages. Suppose, for example, that research reveals a candidate
for a male ancestor's father but does not prove the relationship. If DNA
samples from living male-line descendants of both men are different, they will
disprove the hypothesis. If the samples match, however, the DNA alone does not
© Ugo A. Perego, ugo@smgf.org; Ann Turner, M.D., DNACousins@aol.com; Jayne E. Ekins, jayne@smgf
.org; and Scott R. Woodward, Ph.D., scott@smgf.org. Mr. Perego is director of operations for the Sorenson
Molecular Genealogy Foundation (SMGF), where he supervises the collecting of genetic and genealogical data
for the foundation's worldwide database. In the past five years, he has written a dozen articles and given more
than one hundred lectures on molecular genealogy. Dr. Turner founded the GENEALOGY-DNA mailing list
at RootsWeb and co-authored (with Megan Smolenyak) Trace Your Roots with DNA: Using Genetic Tests to
Explore Your Family Tree (Emmaus, Pa.: Rodale, 2004). Ms. Ekins, a research scientist with SMGF, coordinates
genetic data production and analysis and performs original research. Dr. Woodward, whose work has been
featured internationally, is chief scientific officer for SMGF and principal investigator for the molecular
genealogy research project. His research interests include reconstructing ancient and modern genealogies using
DNA techniques on samples worldwide, tracing human population movements by following gene migrations,
and analyzing DNA found in ancient manuscripts.
NATIONAL GENEALOGICAL SOCIETY QUARTERLY 93 (DECEMBER 2005): 245–59
prove a father-son relationship but, in combination with documentary evidence,
it could make the case persuasive.1
GENEALOGICALLY USEFUL PATHWAYS OF GENETIC INHERITANCE
Each parent contributes approximately half of his or her child's DNA. Scientists
usually cannot identify which parent provided which part of the child's
DNA without testing one or both parents. The parts that researchers can identify,
however, allow them to answer many genealogical questions: the Y chromosome,
which is found in each cell's nucleus in males only, and mitochondrial DNA
(mtDNA), which is found in each cell's cytoplasm. See figure 1.
The Paternal Lineage Pathway
Sons receive a Y chromosome, usually unchanged, from their fathers. Occasionally,
however, a slight alteration (called a "mutation") will occur in a random
male's Y chromosome. A man with such an altered Y chromosome will pass it to
his sons and they to their sons. Subsequently, all of their male-line descendants
will pass that slightly altered Y chromosome to their sons. Further random mutations
may occur occasionally in later generations. Thus, every living male's Y
chromosome today carries a cumulative history of many small changes that have
occurred in his paternal lineage over hundreds of generations and thousands of
1. Several recent books cover the basic biology of genetics and DNA as they apply to genealogical testing.
See, for example, Chris Pomery, DNA and Family History (Toronto, Ont.: Dundurn, 2004); Thomas H.
Shawker, Unlocking Your Genetic History (Nashville, Tenn.: Rutledge Hill, 2004); and Smolenyak and Turner,
Trace Your Roots with DNA.
National Genealogical Society Quarterly 246
years. Because different changes occurred in different males over the millennia,
their male descendants bear Y chromosomes with distinctive patterns, called
"haplotypes," which can differentiate their families and ancestors.
The Y chromosome is useful for answering genealogical questions because it
passes intact from generation to generation and its inheritance follows surnames
in many western and some nonwestern societies. All male-line descendants of the
same male ancestor—typically those with the same surname in these societies—
will have the same or a very similar Y chromosome.2 For example, residents of
Tristan da Cunha, which has genealogical records dating from 1816, have eight
Y-chromosome haplotypes corresponding to those of seven of the island's
founders, whose surnames the residents bear, and an apparent visitor with an
unknown surname.3 In cases where the Y-chromosome haplotype did not correspond
to the surname, it indicated ancestry more accurately than documentary
genealogy or oral history.
Searching a database of Y-chromosome haplotypes paired with surnames can
enable genealogists to identify relatives and disprove erroneous lineages. Males
with the same surname and different haplotypes probably descend from different
lines bearing the same surname. Conversely, similar haplotypes of males with
different surnames might indicate adoption, illegitimacy, or other situations
where names may have been altered somewhere in a male-line descent. For
example, men with Lorentz and Lawrence surnames and the same Y-chromosome
haplotype very likely descend from the same male-line ancestor.4
Two studies popularized applying Y-chromosome analysis to genealogical research,
the highly publicized Jefferson-Hemings case and a study involving the
Jewish priestly class of Cohen:
• The question of whether Thomas Jefferson fathered some or all of his slave Sally
Hemings's children arose during his lifetime, and it is still the subject of debate
today. Jefferson left no male issue through his wife, but living male-line descendants
of his father's brother, who carried the same Y chromosome as Jefferson, were tested
to determine the Jefferson haplotype. Also tested were male-line descendants of
(1) Jefferson's brother-in-law John Carr (because of rumors that members of his
family had fathered Hemings's children), (2) Sally Hemings's son Thomas Woodson,
and (3) another Hemings son, Eston. Of the three lines, only the male-line
descendants of Eston Hemings carry the Jefferson Y-chromosome haplotype.5 The
2. Bryan Sykes and Catherine Irven, "Surnames and the Y Chromosome," American Journal of Human
Genetics 66 (March 2000): 1417–19; and Mark A. Jobling, "In the Name of the Father: Surnames and Genetics,"
TRENDS in Genetics 17 (June 2001): 353–57.
3. Himla Soodyall and others, "Genealogy and Genes: Tracing the Founding Fathers of Tristan da
Cunha," European Journal of Human Genetics 11 (September 2003): 705–9.
4. Ann Turner, "One or Many? Ann Turner Looks at the Role of DNA in the Study of Surname Origins,"
Family Chronicle 9 (March/April 2005): 46–49.
5. Eugene A. Foster and others, "Jefferson Fathered Slave's Last Child," Nature 396 (5 November 1998):
27–28.
The Science of Molecular Genealogy 247
DNA evidence alone does not prove that Jefferson was Eston's father, but it
complements evidence drawn from other sources.6
• Researchers found that a noticeable fraction of Jewish priests share a common
Y-chromosome haplotype, whether or not they are part of the far-flung
Ashkenazi or Sephardic communities.7 A later study found the same haplotype in
the Lemba of southern Africa, a tribe with customs reminiscent of Jewish practices
and an oral tradition that their ancestors came from the north by boat.8 Finding the
same haplotype in geographically dispersed groups implies descent from a single
common ancestor.
Businessman Bennett Greenspan hoped that the approach used in the Jefferson
and Cohen research would help family historians. After reaching a brick wall
on his mother's surname, Nitz, he discovered an Argentine researching the same
surname. Greenspan enlisted the help of a male Nitz cousin. A scientist involved
in the original Cohen investigation tested the Argentine's and Greenspan's cousin's
Y chromosomes. Their haplotypes matched perfectly. Furthermore, the haplotype
did not match any of two dozen samples collected by Greenspan to serve
as controls. Fortified by this demonstration that DNA could reflect a common
lineage, Greenspan founded a private company offering DNA tests for genealogical
purposes. His business was shortly followed by a half-dozen similar companies
in the United States and Europe.9
More than two thousand Y-chromosome surname studies are underway, some
with hundreds of participants.10 Family historians interested in joining a project
can find lists of active investigations on commercial testing company Web sites
and Ancestry.com and Genforum.com message boards.11 Many surname-project
Web sites report genetic findings, and genealogical periodicals are beginning to
carry case studies that include Y-chromosome analyses. Several examples demonstrate
different genealogical uses of Y-chromosome data:
• Hundreds of men named Wells participated in Y-chromosome testing. Genealogical
data collected prior to the project suggested twenty-four distinct families. The
6. Helen Leary, "Sally Hemings's Children: A Genealogical Analysis of the Evidence," and Thomas W.
Jones, "The 'Scholars Commission' Report on the Jefferson-Hemings Matter: An Evaluation by Genealogical
Standards," NGS Quarterly 89 (September 2001): 165–207 and 208–18.
7. Mark G. Thomas and others, "Origins of Old Testament Priests," Nature 394 (9 July 1998): 138–40.
8. Mark G. Thomas and others, "Y-chromosomes Traveling South: The Cohen Modal Haplotype and the
Origins of the Lemba—the 'Black Jews of Southern Africa'," American Journal of Human Genetics 66 (February
2000): 674–86.
9. Bennett Greenspan, "An Insider's Look at the Genealogy DNA Field," New England Ancestors
(Summer 2004): 21–23.
10. Bill Davenport, "Surname Projects: 'Over Fifty List'," World Families Network (http://worldfamilies.net/
over50list.html).
11. The largest companies with family DNA projects are DNA Heritage (http://www.dnaheritage.com),
Family Tree DNA (http://www.familytreedna.com), and Relative Genetics (http://www.relativegenetics.com).
A more complete listing can be found at Megan Smolenyak Smolenyak, "Genetealogy Resources," Genetealogy.
com (http://genetealogy.com).
National Genealogical Society Quarterly 248
Y-chromosome surname study, however, demonstrates that five presumed connections,
based on similar names, dates, and places, are separate lines.12
• Y-chromosome samples from just two people solved a problem that had baffled
researchers for years. Justin Howery and Fred Hauri, who believed that everyone
with a variant of their surnames descends from a man who lived in the 1400s in the
Swiss village of Beromuenster, could not document a family connection. Genetic
testing, however, revealed that both men have the same Y-chromosome haplotype,
even though their ancestors came to the United States from different countries in
different centuries.13
• Although all Smolenyaks seem to trace their ancestry to one small village in
Slovakia, they have four Y-chromosome haplotypes, indicating four distinct ancestral
lines.14
• The ancestral haplotype of Edmund Rice, who immigrated to Massachusetts in
1638, was established by matching DNA results from descendants of five different
sons. The testing also revealed a "non-paternity event"—possibly an unrecorded
adoption or illegitimacy—in one line of male descent.15
The Maternal Lineage Pathway
In addition to the DNA in the nucleus of most cells, DNA is also found in
structures called mitochondria in each cell's cytoplasm. See figure 1. Cells have
hundreds of mitochondria, each containing many DNA molecules called "mitochondrial
DNA" or "mtDNA." The mother's—but not the father's—
mitochondria are present in the fertilized egg that is the first cell of a new human
being. Thus, a mother passes her mtDNA to her sons and daughters. Her daughters,
but not her sons, pass their mtDNA to the next generation. Consequently,
mtDNA, inherited exclusively from mothers, passes intact from generation to
generation.
Just as with the Y chromosome, slight random changes in mtDNA molecules
over many generations result in different patterns or haplotypes. However, these
mutations occur less frequently than in Y chromosomes. The mutation rate has
been measured in Iceland, which has genealogical records covering many generations.
Only three mutations occurred in 705 "transmission events" (opportunities
for a mutation to occur between generations). Some of the residents with
matching mtDNA haplotypes were twelve generations removed from their common
female-line ancestor, who was born in 1560.16
12. Ken Wells, "Relative Advance: DNA Testing Helps Find Family Roots," Wall Street Journal, 6 March,
2003, page A1.
13. Justin Howery, "Howery DNA Project," message board posting, 17 November 2000, GENEALOGYDNA-
L Archives (http://archiver.rootsweb.com/th/read/GENEALOGY-DNA/2000–11/0974503831).
14. Megan Smolenyak Smolenyak, "DNA Testing Dispels a Genealogical Myth," Everton's Family History
Magazine 56 (May/June 2002): 44–48.
15. Robert V. Rice and John F. Chandler, "DNA Analyses of Y-chromosomes Show Only One of Three
Sons of Gershom Rice to be a Descendant of Edmund Rice," New England Ancestors 3 (Fall 2002): 50–51.
16. Sigrun Sigurgardottir and others, "The Mutation Rate in the Human mtDNA Control Region,"
American Journal of Human Genetics 66 (May 2000): 1599–1609.
The Science of Molecular Genealogy 249
The popularity of mtDNA for genealogical purposes followed the use of
mtDNA to confirm the identity of remains thought to be those of the wife and
children of Nicholas II, czar of Russia. The mtDNA extracted from the remains
matched that of living relatives who shared a common maternal line with the
czar's wife.17 Such testing can disprove relationships as well: the mtDNA of
Anna Anderson Manahan, who claimed to be Nicholas's daughter Anastasia, did
not match that of the czar's family.18
Ethnic and Geographic Pathways
"Autosomes" are twenty-two pairs of chromosomes that children inherit from
both parents, and the DNA they contain is called "autosomal DNA." Autosomes
do not include the sex chromosomes (X and Y) and mtDNA. In contrast to
mtDNA and Y-chromosome molecules, which parents pass intact to their children,
autosomal DNA comprises a random combination of both parents' genetic
makeup. Because each parent's autosomal DNA recombines, the half that each
transmits to a child is a mixture of the DNA that the contributing parents
received from their parents. Consequently, if neither parent's autosomal DNA is
studied, it is not possible to determine which parent or ancestor contributed any
segment of the child's autosomal DNA. In addition, the proportion of ancestral
genetic contribution to a descendant decreases with the number of generations
between the ancestor and descendant. Both the recombination of autosomal
DNA and its decreasing proportions over generations create challenges for using
autosomal DNA for genealogical purposes.
Autosomal DNA is the focus of techniques to determine origins more generally
than paternal and maternal lines allow. Genealogists can submit DNA
samples to a company that tests autosomal DNA to identify continental or
subcontinental origins.19 In a broad sense, individuals can use the results to
reconnect with family roots that may have been previously unknown to them.
Other research has focused on inferring ancestry more specific than broad
geographic or ethnic classifications. A recently proposed approach allows a participant's
assignment to a hierarchical set of populations. For example, the firstlevel
test results may imply European origins. Subsequent levels may narrow the
inference successively to the British Isles, a region in southwest Wales, and
perhaps an extended family from the area. Such inference of ancestry from all
17. Peter Gill and others, "Identification of the Remains of the Romanov Family by DNA Analysis,"
Nature Genetics 6 (February 1994): 130–35. Recent publications have challenged the findings on the basis of
difficulties involved in recovering and analyzing ancient DNA. See Alex Knight and others, "Molecular,
Forensic and Haplotypic Inconsistencies Regarding the Identity of the Ekaterinburg Remains," Annals of Human
Biology 31 (March–April 2004): 129–38.
18. Peter Gill and others, "Establishing the Identity of Anna Anderson Manahan," Nature Genetics 9
(January 1995): 9–10.
19. Tony Frudakis and others, "A Classifier for SNP-Based Racial Inference," Journal of Forensic Science 48
(July 2003): 771–82. For further information, see Tony N. Frudakis, "Powerful but Requiring Caution: Genetic
Tests of Ancestral Origins," in the present issue of the NGS Quarterly.
National Genealogical Society Quarterly 250
areas of the world is possible, but accuracy depends on the depth of sampling from
each region. Participants receive "likelihood scores" for each level, which enable
them to weigh the results. Assignment to broad ethnic and geographic classifications
applies to questions of deeply rooted ancestry. In contrast, inferring
membership in more localized populations can provide information on a genealogically
useful scale.20
DNA IN THE LABORATORY
Today commercial laboratories apply techniques that are spin-offs from the
Human Genome Project, the massive international collaboration to analyze the
complete set of human chromosomes.21 Nevertheless, current technology has not
yet advanced to the point where laboratories can report an individual's entire
genetic makeup.22 Instead, specialized tests analyze limited sections of DNA to
help solve problems in areas including crime investigation, paternity, identification
of human remains, and genealogy.
Mitochondrial DNA Sequences
DNA consists of long sequences of four chemical compounds. These building
blocks—called "bases" or "nucleotides"—are often abbreviated as A (adenine), C
(cytosine), G (guanine), and T (thymine). Scientists were initially skeptical that
such a limited set of chemicals could account for the complexity of life. However,
the four bases can be arranged in many different orders, just as letters from the
English alphabet can be shuffled in many different combinations and chained
together into a complete book. The human genome contains about three billion
bases. Some of its sections can be decoded, but a surprisingly large amount,
perhaps as much as 98 percent, appears to be meaningless. Genealogical tests
focus on these regions of "junk" DNA, and thus they cannot reveal any personal
traits or medical conditions. For an example of a short sequence of DNA bases,
see table 1.
A cell's mtDNA contains 16,569 sequenced bases but, for genealogical questions,
laboratories typically study segments containing only 400 to 1,100 of the
most informative bases. These sections are called "hypervariable" because they
show more differences among people than mtDNA's other regions. Because a
report listing even 400 bases would be difficult to interpret, laboratories conducting
mtDNA tests customarily report only the bases that differ from a standard
sequence called the Cambridge Reference Sequence (CRS). For example, a re-
20. Jayne E. Ekins and others, "Inference of Ancestry: Constructing Hierarchical Reference Populations
and Assigning Unknown Individuals," Human Genomics (forthcoming).
21. "The Human Genome Project Completion: Frequently Asked Questions," National Human Genome
Research Institute (http://www.genome.gov/11006943).
22. Corie Lok, in "Deciphering DNA, Top Speed," TechnologyReview.com (http://www.technologyreview
.com/articles/05/05/issue/forward_dna.asp?p=1), writes "Using about 100 state-of-the-art sequencing machines
to fully sequence the 3.2 billion DNA letters that make up one person's genome would take six months and cost
$20 million to $30 million."
The Science of Molecular Genealogy 251
port of an "HVR 1" test result as "16093C" would mean that the subject's
mtDNA in hypervariable region one (HVR 1)—an mtDNA segment containing
bases in positions numbered 16,024 through 16,365—differs from the CRS because
it has a cytosine (C) base at position 16,093. Most people have a few
differences from the CRS.
The Smallest Changes in DNA
As described above, mutations are modifications in DNA molecules that
occur randomly. Mutations can have positive or negative effects, but they typically
occur in sections of DNA that have no effect. A mutation that replaces just
one base (nucleotide) with another is called a "single nucleotide polymorphism"
or "SNP" (pronounced "snip"). For an example, see table 1.
The changes in the mtDNA molecule described above are literally SNPs, but
more often the term is applied to SNPs sprinkled throughout the chromosomes,
including the Y. SNPs, which tend to be rare, often represent unique events.
Given their low rate, SNPs are used in anthropological studies for tracing extremely
deeply rooted pedigrees, for example, determining matrilineal or patrilineal
descent from one of several ancient "clans."23
By using multiple SNPs researchers can determine the order in which the
SNPs occurred and estimate when two ancient lineages diverged. See table 2.
The variability of SNPs among descendants of a "founding father" gives a rough
estimate of when he lived: the more SNPs the descendants have, the more time
has elapsed since their lineages diverged. For example, The Y Chromosome
Consortium has identified a set of SNPs useful in classifying males into hierarchically
related clusters. Small clusters with identical haplotypes can be combined
into larger groups with similar but not identical haplotypes and so forth
23. Bryan Sykes, The Seven Daughters of Eve: The Science that Reveals our Genetic Ancestry (New York:
W. W. Norton, 2001).
National Genealogical Society Quarterly 252
until the groups are joined into a tree representing all humankind. The clusters,
labeled in a systematic alphanumeric fashion similar to an outline, comprise
haplogroups and subhaplogroups.24 Because different haplogroups predominate in
different regions of the world, Y-chromosome and mtDNA haplogroups suggest
ethnic and geographic origins of patrilineal and matrilineal ancestry—for example
a man in Y-chromosome group R1b might have male-line ethnic origins in
Western Europe.25
The Most Genealogically Useful Changes in DNA
The genetic information that genealogists most often employ is the "short
tandem repeat" (STR). The term refers to the repetition of a short sequence
of bases. For instance, a sequence of four bases, like G-A-T-A, might occur
seven consecutive times in one segment of DNA. When an STR mutates, the
number of repetitions changes—for example seven repetitions of G-A-T-A at
24. "A Nomenclature System for the Tree of Human Y-Chromosomal Binary Haplogroups," The Y Chromosome
Consortium (http://ycc.biosci.arizona.edu/nomenclature_system/frontpage.html).
25. J. Douglas McDonald, "World Haplogroup Maps," McDonald Group (http://www.scs.uiuc.edu/
∼mcdonald/WorldHaplogroupsMaps.pdf).
The Science of Molecular Genealogy 253
one location on a father's Y chromosome might change to six repetitions of the
same sequence at the same location on his son's Y chromosome. For an example
see table 3. Such mutations pass unchanged from parent to child until another
mutation occurs.
As various distinct STR mutations accumulated in different lineages over
many centuries, each developed its own pattern of STRs. Consequently, people
with different lineages have distinct inherited STR patterns. Individuals with
identical patterns are said to bear the same "haplotype," such as the Jefferson
Y-chromosome haplotype of Eston Hemings's male-line descendants. Minor differences
in haplotypes are compatible with descent from a common ancestor.
Genetic tests determine the pattern of STRs on the Y chromosome. Locations
or segments on the chromosome often have labels starting with the letters DYS
(for example, "DYS439"), which stand for "DNA Y-chromosome sequence."26
Genetics laboratories test between twelve and forty locations on the Y chromosome.
Their reports list the DYS numbers of the locations tested and the number
of STRs in each location—such as 13 at DYS 393. For example, the DNA test
that determined the Jefferson haplotype reported the number of STRs at eleven
DYS locations on a Jefferson descendant's Y chromosome. See table 4.
DNA ON THE INTERNET
Y-chromosome Databases
Most Y-chromosome tests take place on a small scale within surname projects,
such as the Edmund Rice study described above. However, large assemblies of
Y-chromosome data are available on the Internet, which can place an individual's
test results in a global context. Such public databases might generate privacy
26. John M. Butler, Forensic DNA Typing: Biology, Technology, and Genetics of STR Markers (Burlington,
Mass.: Elsevier Academic Press, 2005), 23–25.
National Genealogical Society Quarterly 254
concerns, but they do not reveal personal identities, and their data do not
contain information about personal traits or medical conditions. The rapidly
accumulating volume of online genetic information can aid investigations of
genealogical questions.
Results from the 1998 study of Carr, Jefferson, and Woodson haplotypes
illustrate the useful information that can be gleaned from online databases. A
centerpiece argument was the rarity of the Jefferson haplotype, suggesting that
the Jefferson-Hemings match was not coincidental. When the article was written,
the database of Y-chromosome haplotypes contained 670 European records,
with no matches to the Jefferson haplotype.27 Today, however, such databases
have vastly larger numbers of records:
• Y-chromosome Haplotype Reference Database (YHRD) is an anonymous database
of records submitted by forensic laboratories and collected to provide a cross-sample
of people in specific locations. It contains 28,650 world-wide records, including
18,711 from Europe.28
• Ybase was the first publicly accessible database that allowed individuals who had
used different testing companies to enter their data and compare results. It contains
5,025 Y-chromosome haplotypes, 6,214 surnames, and useful statistical summaries
showing the range of STRs for tested Y-chromosome locations.29
27. Foster and others, "Jefferson Fathered Slave's Last Child," 27–28.
28. "About the 'YHRD - Y Chromosome Haplotype Reference Database'," YHRD.org (http://www.yhrd
.org).
29. Ybase: Genealogy by Numbers (http://www.ybase.org).
The Science of Molecular Genealogy 255
• Ysearch is a publicly accessible database containing approximately thirteen thousand
Y-chromosome records with the large majority having test results for twelve to
twenty-four markers. Anyone can manually add data obtained from any company,
and an automated procedure is available for Family Tree DNA customers. Users can
add genealogical information to their Y-chromosome records.30
• The Sorenson Molecular Genealogy Foundation (SMGF) database includes 13,489
Y chromosomes linked to 550,000 ancestors.31 With 9,400 unique surnames and
more than 90 percent of the Y-chromosome haplotypes tested at thirty or more
markers, it is the largest searchable Y-chromosome database. SMGF analyzes
samples contributed by volunteers, who can order a free participation kit from the
Web site.32
• Ymatch contains thirty-five hundred records with the majority having test results
for twenty-six to forty-three Y-chromosome locations. This is the newest database
of this kind available to the public.33
None of the above sources contains a match for the Jefferson haplotype. In
contrast, the Sorenson database has 531 records, with many different surnames,
matching the Carr haplotype shown in table 4, which was based on eleven
markers (seven markers, when applying modern standards). Testing more markers
on the Carr sample, as various companies do today, would reduce the matches to
those most closely related to the Carrs who were tested.
The results for the Woodson haplotype, depicted in table 4, are instructive.
The Sorenson database has just one match, a sample from Ghana. That does not
necessarily mean that the Woodson line came from Ghana—a larger database
could show matches in other localities. However, this result suggests that the
haplotype is more typical of African ancestry than European. Such geographical
information may shed light on ancestral lines that lack documentary evidence for
their origins.
Mitochondrial DNA Databases
Just as with Y-chromosome analysis, a person with mtDNA test results can
compare them with various online databases. DNA data for the "Ice Man"
demonstrate the information available. A body discovered in 1991 at the edge of
a melting Alpine glacier was initially thought to be a climber who had died in
modern times. Scientists soon determined, however, that the remains were some
five thousand years old.34 The Ice Man had a relatively common mtDNA haplotype
present in 1 to 2 percent of Europeans. Containing two differences from
30. Ysearch (http://www.ysearch.org).
31. Ugo A. Perego, Natalie M. Myres, and Scott R. Woodward, "'Y' Research Through DNA," Everton's
Family History Magazine 58 (May–June 2004): 26–28.
32. Sorenson Molecular Genealogy Foundation (http://www.smgf.org).
33. Relative Genetics (http://www.relativegenetics.com).
34. Oliva Handt and others, "Molecular genetic analyses of the Tyrolean Ice Man," Science 264 (17 June
1994): 1775–78.
National Genealogical Society Quarterly 256
the Cambridge Reference Sequence (CRS), his sample had cytosine (C) bases at
positions 16,224 and 16,311 in hypervariable region 1.35
The following online databases contain mtDNA test results:
• MitoMap lists positions where differences from the CRS have been reported. These
are listed by mtDNA location number rather than as a composite haplotype. However,
it can be seen that many studies have reported differences. Occasional individuals
have a novel difference, one never previously described.36
• The Mitochondrial DNA Concordance is a collection of several thousand mtDNA
haplotypes reported in the technical literature up to about 1998.37 The Ice Man's
mtDNA haplotype (16224[C] 16311[C]) can be found in two places, under
the listings for locations 16,224 or 16,311. The database shows that the Ice
Man's haplotype occurs in many European populations—some Basque, Bavarian,
Bulgarian, Cornish, English, Finnish, German, Norwegian, Portuguese, Swiss,
Tuscan, and Welsh people have the same haplotype. Thus it is not possible to
ascribe the Ice Man's ancestral line to a specific European location; however,
because the haplotype is not found on other continents, the broad classification of
European ancestry is confirmed.
• Oxford Ancestors offers guest access to its database. Entering the Ice Man's mtDNA
test results shows 250 matches. Oxford Ancestors classifies him as a member of the
"Katrine" clan, a pseudonym for mitochondrial haplogroup K.38
• Mitosearch is a public-access database of individually contributed GEDCOM files
and mtDNA test results that have not been independently verified. A recent survey
of the database produced fifty-eight matches for the Ice Man. It also yielded 150
members of haplogroup K. They had the Ice Man's two differences from the CRS
plus various additions, demonstrating variation within a haplogroup.39
• The mtDNA Log functions like a guest book. Contributors may leave free-form
comments along with their mtDNA test results. The site does not have a search
function, but the Web browser's "Find" function substitutes. Visitors often provide
data about their ancestral names and geographical locations.40
• The Federal Bureau of Investigation maintains an "mtDNA Population Database,"
which incorporates sequences from the Mitochondrial DNA Concordance (above)
as well as more recent contributions from accredited forensic testing laboratories.
This anonymous database can reveal whether a haplotype is common or rare.41
35. Michael D. Coble and others, "Single Nucleotide Polymorphisms Over the Entire mtDNA Genome
that Increase the Power of Forensic Testing in Caucasians," International Journal of Legal Medicine 118 (June
2004): 137–46.
36. MITOMAP: MtDNA Control Region Sequence Polymorphisms (http://www.mitomap.org/cgi-bin/
mitomap/tbl6gen.pl : dated 27 September 2005).
37. Kevin Miller and John Dawson, Mitochondrial DNA Concordance (http://www.bioanth.cam.ac.uk/
mtDNA/).
38. "Oxford Ancestors' Databases," Oxford Ancestors (http://oxfordancestors.com/members).
39. Mitosearch (http://www.mitosearch.org).
40. Charles F. Kerchner Jr., Mitochondria DNA (mtDNA) Test Results Log (BLOG) (http://www.kerchner
.com/cgi-kerchner/mtdna.cgi).
41. Keith L. Monson and others, "The mtDNA Population Database: An Integrated Software and Database
Resource for Forensic Comparison," Forensic Science Communications 4 (April 2002), electronic edition
(http://www.fbi.gov/hq/lab/fsc/backissu/april2002/miller1.htm).
The Science of Molecular Genealogy 257
• GenBank is a repository at the National Institutes of Health for raw mtDNA
sequences from technical literature. With some effort public users can align their
sequences to the published data and compare the results.42
• Many individuals have developed custom Web sites devoted to a specific haplogroup.
The World Families Network maintains a page of links to these special
interest groups.43 For instance, John Walden's Web site for haplogroup K diagrams
the relationships between the "clan mother" for haplogroup K and the variations he
has located. 44
DNA TESTING IN THE FUTURE
In years to come DNA tests probably will be faster and cheaper and will
include more markers than today's tests. Publicly accessible databases of compiled
genetic information will also continue to grow, allowing genealogists to correlate
DNA test results with population-based studies, such as the National Geographic
Society's recently launched Genographic Project.45 Large databases containing
mtDNA and Y-chromosome matches could suggest research pathways that might
unblock a lineage problem that seems unsolvable with documentary research
alone.
The bulk of current tests for genealogical purposes is limited to the Y chromosome
and mtDNA. This is a severe constraint because straight paternal and
maternal lineages represent only a tiny fraction of anyone's total ancestry and
DNA. The other parts of the pedigree harbor vast amounts of information that
future genetic testing might unlock. Laboratories are beginning to study the use
of autosomal DNA for genealogical purposes.
CONCLUSION
Molecular genealogy synthesizes traditional genealogical research and relatively
new technologies developed to explore genetic characteristics of the
world's people. The combination enhances traditional genealogical methods,
especially when ambiguities and roadblocks in written records impede documentary
research. Scientific methods are just beginning to tap into the invaluable
repository of ancestral information that is carried in every individual's DNA.
Molecular methods can help individuals uncover previously unknown family
relationships, verify or refute claims to ancestry, and shed light on questions that
have puzzled genealogists for years.
Currently the two most active areas of genetic testing for genealogical purposes
focus on mtDNA and the Y chromosome. DNA projects for family history
42. "GenBank Overview," National Center for Biotechnology Information (http://www.ncbi.nlm.nih.gov/
Genbank/).
43. "mtDNA—The Family of Woman," World Families Network (http://worldfamilies.net/mtDNA.htm).
44. John S. Walden, "Swinging in the mtDNA Tree," Walden/Adams/Walts/Waltz Surname DNA Projects
(http://freepages.genealogy.rootsweb.com/∼jswdna/mtdna.html).
45. NationalGeographic.com, The Genographic Project (https://www3.nationalgeographic.com/
genographic).
National Genealogical Society Quarterly 258
purposes can use samples from only two participants or hundreds. Many questions
can be approached by querying online searchable genetic databases to find genetic
matches to a known DNA profile. These remarkable resources are freely
available and continuously expanding. Molecular genealogy methods eventually
will enable genealogists to explore lines beyond strictly matrilineal and patrilineal
ancestry. In the near future genealogists can expect a burgeoning expansion
of this field. Genetic testing will be more widely available, increasingly economical
for the individual, and more informative for answering a greater variety of
genealogical questions.
Emigrated Before Birth?
[William Spreen declaration of intent, Taylor County, Wisconsin, Declarations
of Intention 4: 408, Wisconsin Historical Society, Madison; microfilm 2,134,516,
Family History Library, Salt Lake City, Utah. Underlined portions are handwritten
on a printed form.]
I, William Spreen, aged 28 years, occupation Farmer, do declare on oath that my
personal description is: Color White, complexion Light, height 5 feet 7 inches,
weight 145 pounds, color of hair Brown, color of eyes Blue[,] other visible distinctive
marks None; I was born in New Stetten, Germany, on the 19 day of
January, anno Domini 1890; I now reside at Medford Wisconsin. I emigrated to
the United States of America from Old Stetten, Germany on the vessel Unknown;
my last foreign residence was New Stetten, Germany. It is my bona fide
intention to renounce forever all allegiance and fidelity to any foreign prince,
potentate, state, or sovereignty, and particularly to William II German Emperor,
of which I am now a subject; I arrived at the port of New York, in the State of
New York on or about the 15 day of June, anno Domini 1889; I am not an
anarchist; I am not a polygamist nor a believer in the practice of polygamy; and
it is my intention in good faith to become a citizen of the United States of
America and to permanently reside therein: So help me God. William Spreen
(original signature of declarant.) Subscribed and sworn to before me this 8th day
of January, anno Domini 1919. (seal) S. A. McComber, Clerk of the Circuit
Court.
—Contributed by Joy Reisinger, CG
The Science of Molecular Genealogy 259