The identification and dating of the Y chromosome of an American Adam

We analyzed the allelic polymorphisms in seven Y-specific microsatellite loci and a Y-specific alphoid system with 27 variants (“hl-XXVII). A total of 53 Y chromosomes carrying the DYS 199T allele and belonging to Amerindian (51) and Na-Dene (2) linguistic groups were studied. The information gathered allowed us to identify the ancestral founder haplotype (0A) and to recognize 7 derived haplogroups diverging from 0A by 1-7 mutational steps. The 0A haplotype was the most frequent and had the following allele constitution: DYS199T; “hll; DYS19/13; DYS389A/10; DYS389b/27; DYS390/24; DYS39I 10; DYS392/ 14; DYS393/13 (microsatellite alleles are indicated as number of repeats). All native Americans had the DYS 199T allele and the “hll form. Since there are no indications of recurrency for the DYSI99C>T transition, we concluded that all DYS199T haplotypes were derived from a single individual in which the C>T mutation occurred for the first time; we call this individual a “New World Adam”. We analyzed the Y-specific microsatellite mutation rate in 1743 father-son transmissions and we pooled our data with equivalent information in literature to obtain an average rate of 0.0018. We could estimate that the 0A haplotype has an average age of 33,750 years (minimum 20,250 and maximum 88,050 years). DYS 199T allele is found in 85-90% of Amerindian chromosomes indicating that 0A haplotype is the most prevalent or perhaps the only founder paternal lineage of New World aborigines.Instituto Multidisciplinario de Biología Celula

The identification and dating of the Y chromosome of an American Adam

We analyzed the allelic polymorphisms in seven Y-specific microsatellite loci and a Y-specific alphoid system with 27 variants (“hl-XXVII). A total of 53 Y chromosomes carrying the DYS 199T allele and belonging to Amerindian (51) and Na-Dene (2) linguistic groups were studied. The information gathered allowed us to identify the ancestral founder haplotype (0A) and to recognize 7 derived haplogroups diverging from 0A by 1-7 mutational steps. The 0A haplotype was the most frequent and had the following allele constitution: DYS199T; “hll; DYS19/13; DYS389A/10; DYS389b/27; DYS390/24; DYS39I 10; DYS392/ 14; DYS393/13 (microsatellite alleles are indicated as number of repeats). All native Americans had the DYS 199T allele and the “hll form. Since there are no indications of recurrency for the DYSI99C>T transition, we concluded that all DYS199T haplotypes were derived from a single individual in which the C>T mutation occurred for the first time; we call this individual a “New World Adam”. We analyzed the Y-specific microsatellite mutation rate in 1743 father-son transmissions and we pooled our data with equivalent information in literature to obtain an average rate of 0.0018. We could estimate that the 0A haplotype has an average age of 33,750 years (minimum 20,250 and maximum 88,050 years). DYS 199T allele is found in 85-90% of Amerindian chromosomes indicating that 0A haplotype is the most prevalent or perhaps the only founder paternal lineage of New World aborigines.Instituto Multidisciplinario de Biología Celula

Geographic patterns of genome admixture in latin American mestizos

The large and diverse population of Latin America is potentially a powerful resource for elucidating the genetic basis of complex traits through admixture mapping. However, no genome-wide characterization of admixture across Latin America has yet been attempted. Here, we report an analysis of admixture in thirteen Mestizo populations (i.e. in regions of mainly European and Native settlement) from seven countries in Latin America based on data for 678 autosomal and 29 X-chromosome microsatellites. We found extensive variation in Native American and European ancestry (and generally low levels of African ancestry) among populations and individuals, and evidence that admixture across Latin America has often involved predominantly European men and both Native and African women. An admixture analysis allowing for Native American population subdivision revealed a differentiation of the Native American ancestry amongst Mestizos. This observation is consistent with the genetic structure of pre-Columbian populations and with admixture having involved Natives from the area where the Mestizo examined are located. Our findings agree with available information on the demographic history of Latin America and have a number of implications for the design of association studies in population from the region.La lista completa de autores que integran el documento puede consultarse en el archivo.Instituto Multidisciplinario de Biología Celula

Geographic patterns of genome admixture in latin American mestizos

The large and diverse population of Latin America is potentially a powerful resource for elucidating the genetic basis of complex traits through admixture mapping. However, no genome-wide characterization of admixture across Latin America has yet been attempted. Here, we report an analysis of admixture in thirteen Mestizo populations (i.e. in regions of mainly European and Native settlement) from seven countries in Latin America based on data for 678 autosomal and 29 X-chromosome microsatellites. We found extensive variation in Native American and European ancestry (and generally low levels of African ancestry) among populations and individuals, and evidence that admixture across Latin America has often involved predominantly European men and both Native and African women. An admixture analysis allowing for Native American population subdivision revealed a differentiation of the Native American ancestry amongst Mestizos. This observation is consistent with the genetic structure of pre-Columbian populations and with admixture having involved Natives from the area where the Mestizo examined are located. Our findings agree with available information on the demographic history of Latin America and have a number of implications for the design of association studies in population from the region.La lista completa de autores que integran el documento puede consultarse en el archivo.Instituto Multidisciplinario de Biología Celula

The identification and dating of the Y chromosome of an American Adam

We analyzed the allelic polymorphisms in seven Y-specific microsatellite loci and a Y-specific alphoid system with 27 variants (“hl-XXVII). A total of 53 Y chromosomes carrying the DYS 199T allele and belonging to Amerindian (51) and Na-Dene (2) linguistic groups were studied. The information gathered allowed us to identify the ancestral founder haplotype (0A) and to recognize 7 derived haplogroups diverging from 0A by 1-7 mutational steps. The 0A haplotype was the most frequent and had the following allele constitution: DYS199T; “hll; DYS19/13; DYS389A/10; DYS389b/27; DYS390/24; DYS39I 10; DYS392/ 14; DYS393/13 (microsatellite alleles are indicated as number of repeats). All native Americans had the DYS 199T allele and the “hll form. Since there are no indications of recurrency for the DYSI99C>T transition, we concluded that all DYS199T haplotypes were derived from a single individual in which the C>T mutation occurred for the first time; we call this individual a “New World Adam”. We analyzed the Y-specific microsatellite mutation rate in 1743 father-son transmissions and we pooled our data with equivalent information in literature to obtain an average rate of 0.0018. We could estimate that the 0A haplotype has an average age of 33,750 years (minimum 20,250 and maximum 88,050 years). DYS 199T allele is found in 85-90% of Amerindian chromosomes indicating that 0A haplotype is the most prevalent or perhaps the only founder paternal lineage of New World aborigines.Instituto Multidisciplinario de Biología Celula

La aventura de la ciencia : De los cromosomas a los genes y otras andanzas

Varias veces me invitaron a escribir una reseña de mi actividad como científico y hasta el presente nunca había aceptado hacerlo. Toda tarea humana implica un entrelazado de acciones con otras personas y aún para la Ciencia la forma en que se almacenan los recuerdos de las circunstancias que precedieron y condujeron a un determinado resultado es diferente en la memoria de cada uno de los participantes. El temor a favorecer solo mi visión de los hechos explica mi reticencia a documentarlos en un texto. Creo, sin embargo, que ha llegado el momento de asumir el desafío; el riesgo de presentar un relato sesgado aún persiste pero dado el tiempo transcurrido entre los acontecimientos y el presente es preferible relatar una parte de ellos a perderlos por completo.Instituto Multidisciplinario de Biología Celula

Aspectos legales y éticos vinculados con el establecimiento y uso de los reservorios y bancos de ADN humano

La utilidad de los depósitos de material genético humano para la investigación médica, antropológica y básica es indiscutible. Los repositorios y bancos permiten compartir las muestras entre distintos laboratorios de investigación, efectuar nuevos ensayos moleculares en muestras representativas de distintos grupos étnicos o de diversas enfermedades genéticas o hereditarias, acelerar y abaratar la obtención de resultados evitando la implementación de colectas de material biológico cada vez que se inicia un nuevo proyecto científico. Sin embargo, la organización de un repositorio o banco de material genético es compleja, involucra a varias partes (donantes, representantes legales del repositorio o banco, usuarios del material depositado) y a distintas entidades y organismos públicos y privados con y sin fines de lucro, tales como organismos que proveen los fondos para financiar los bancos y repositorios, entidades sede de los bancos y repositorios, comités de ética encargados de autorizar y monitorear los depósitos de material genético, empresas farmacéuticas que realizan investigaciones con fines de lucro, organizaciones no gubernamentales sin fines de lucro que colectan fondos para el establecimiento de reservorios de material genético destinados a mejorar la asistencia médica de determinadas afecciones. Esta multiplicidad de actores con intereses diversos genera también diversas interpretaciones de las cuestiones éticas y legales relacionadas con los depósitos de material genético, las cuales se hacen evidentes al analizar las recomendaciones sobre el tema que hacen distintas organizaciones internacionales tales como UNESCO, HUGO, OMS, Comités de Ética de la Comunidad Europea y de Australia, “American Society of Human Genetics”, “American College of Medical Genetics”.Asociación de Antropología Biológica de la República Argentina (AABRA

Aspectos legales y éticos vinculados con el establecimiento y uso de los reservorios y bancos de ADN humano

La utilidad de los depósitos de material genético humano para la investigación médica, antropológica y básica es indiscutible. Los repositorios y bancos permiten compartir las muestras entre distintos laboratorios de investigación, efectuar nuevos ensayos moleculares en muestras representativas de distintos grupos étnicos o de diversas enfermedades genéticas o hereditarias, acelerar y abaratar la obtención de resultados evitando la implementación de colectas de material biológico cada vez que se inicia un nuevo proyecto científico. Sin embargo, la organización de un repositorio o banco de material genético es compleja, involucra a varias partes (donantes, representantes legales del repositorio o banco, usuarios del material depositado) y a distintas entidades y organismos públicos y privados con y sin fines de lucro, tales como organismos que proveen los fondos para financiar los bancos y repositorios, entidades sede de los bancos y repositorios, comités de ética encargados de autorizar y monitorear los depósitos de material genético, empresas farmacéuticas que realizan investigaciones con fines de lucro, organizaciones no gubernamentales sin fines de lucro que colectan fondos para el establecimiento de reservorios de material genético destinados a mejorar la asistencia médica de determinadas afecciones. Esta multiplicidad de actores con intereses diversos genera también diversas interpretaciones de las cuestiones éticas y legales relacionadas con los depósitos de material genético, las cuales se hacen evidentes al analizar las recomendaciones sobre el tema que hacen distintas organizaciones internacionales tales como UNESCO, HUGO, OMS, Comités de Ética de la Comunidad Europea y de Australia, “American Society of Human Genetics”, “American College of Medical Genetics”.Asociación de Antropología Biológica de la República Argentina (AABRA

Aspectos legales y éticos vinculados con el establecimiento y uso de los reservorios y bancos de ADN humano

La utilidad de los depósitos de material genético humano para la investigación médica, antropológica y básica es indiscutible. Los repositorios y bancos permiten compartir las muestras entre distintos laboratorios de investigación, efectuar nuevos ensayos moleculares en muestras representativas de distintos grupos étnicos o de diversas enfermedades genéticas o hereditarias, acelerar y abaratar la obtención de resultados evitando la implementación de colectas de material biológico cada vez que se inicia un nuevo proyecto científico. Sin embargo, la organización de un repositorio o banco de material genético es compleja, involucra a varias partes (donantes, representantes legales del repositorio o banco, usuarios del material depositado) y a distintas entidades y organismos públicos y privados con y sin fines de lucro, tales como organismos que proveen los fondos para financiar los bancos y repositorios, entidades sede de los bancos y repositorios, comités de ética encargados de autorizar y monitorear los depósitos de material genético, empresas farmacéuticas que realizan investigaciones con fines de lucro, organizaciones no gubernamentales sin fines de lucro que colectan fondos para el establecimiento de reservorios de material genético destinados a mejorar la asistencia médica de determinadas afecciones. Esta multiplicidad de actores con intereses diversos genera también diversas interpretaciones de las cuestiones éticas y legales relacionadas con los depósitos de material genético, las cuales se hacen evidentes al analizar las recomendaciones sobre el tema que hacen distintas organizaciones internacionales tales como UNESCO, HUGO, OMS, Comités de Ética de la Comunidad Europea y de Australia, “American Society of Human Genetics”, “American College of Medical Genetics”.Asociación de Antropología Biológica de la República Argentina (AABRA

Geographic patterns of genome admixture in latin American mestizos

The large and diverse population of Latin America is potentially a powerful resource for elucidating the genetic basis of complex traits through admixture mapping. However, no genome-wide characterization of admixture across Latin America has yet been attempted. Here, we report an analysis of admixture in thirteen Mestizo populations (i.e. in regions of mainly European and Native settlement) from seven countries in Latin America based on data for 678 autosomal and 29 X-chromosome microsatellites. We found extensive variation in Native American and European ancestry (and generally low levels of African ancestry) among populations and individuals, and evidence that admixture across Latin America has often involved predominantly European men and both Native and African women. An admixture analysis allowing for Native American population subdivision revealed a differentiation of the Native American ancestry amongst Mestizos. This observation is consistent with the genetic structure of pre-Columbian populations and with admixture having involved Natives from the area where the Mestizo examined are located. Our findings agree with available information on the demographic history of Latin America and have a number of implications for the design of association studies in population from the region.La lista completa de autores que integran el documento puede consultarse en el archivo.Instituto Multidisciplinario de Biología Celula