RESUMO
The present-day Brazilian population is a consequence of the admixture of various peoples of very different origins, namely, Amerindians, Europeans and Africans. The proportion of each genetic contribution is known to be very heterogeneous throughout the country. The aim of the present study was to compare the male lineages present in two distinct Brazilian populations, as well as to evaluate the African contribution to their male genetic substrate. Thus, two Brazilian population samples from Manaus (State of Amazon) and Ribeirão Preto (State of São Paulo) and three African samples from Guinea Bissau, Angola and Mozambique were typed for a set of nine Y chromosome specific STRs. The data were compared with those from African, Amerindian and European populations. By using Y-STR haplotype information, low genetic distances were found between the Manaus and Ribeirão Preto populations, as well as between these and others from Iberia. Likewise, no significant distances were observed between any of the African samples from Angola, Mozambique and Guinea Bissau. Highly significant Rst values were found between both Brazilian samples and all the African and Amerindian populations. The absence of a significant Sub-Saharan African male component resulting from the slave trade, and the low frequency in Amerindian ancestry Y-lineages in the Manaus and Ribeirão Preto population samples are in accordance with the accentuated gender asymmetry in admixture processes that has been systematically reported in colonial South American populations.
RESUMO
The present-day Brazilian population is a consequence of the admixture of various peoples of very different origins, namely, Amerindians, Europeans and Africans. The proportion of each genetic contribution is known to be very heterogeneous throughout the country. The aim of the present study was to compare the male lineages present in two distinct Brazilian populations, as well as to evaluate the African contribution to their male genetic substrate. Thus, two Brazilian population samples from Manaus (State of Amazon) and Ribeirão Preto (State of São Paulo) and three African samples from Guinea Bissau, Angola and Mozambique were typed for a set of nine Y chromosome specific STRs. The data were compared with those from African, Amerindian and European populations. By using Y-STR haplotype information, low genetic distances were found between the Manaus and Ribeirão Preto populations, as well as between these and others from Iberia. Likewise, no significant distances were observed between any of the African samples from Angola, Mozambique and Guinea Bissau. Highly significant Rst values were found between both Brazilian samples and all the African and Amerindian populations. The absence of a significant Sub-Saharan African male component resulting from the slave trade, and the low frequency in Amerindian ancestry Y-lineages in the Manaus and Ribeirão Preto population samples are in accordance with the accentuated gender asymmetry in admixture processes that has been systematically reported in colonial South American populations.
Assuntos
Humanos , Masculino , Cromossomos Humanos Y/genética , Etnicidade/genética , Repetições de Microssatélites , População Negra , Marcadores Genéticos , Variação Genética , Genética Populacional , Indígenas Sul-AmericanosRESUMO
17 Y-chromosome STR loci (DYS19, DYS389I, DYS389II, DYS390, DYS456, DYS391, DYS392, DYS393, DYS385 a/b, DYS458, DYS439, DYS635, GATA H4.1, DYS437, DYS438 and DYS448) were determined for 303 unrelated males, living in Central Portugal, using the AmpFlSTR YFiler PCR Amplification kit (Applied Biosystems). A total of 287 different haplotypes were found, 272 being unique. The overall haplotype diversity (HD) was determined as 0.9996, a value similar to other YFiler data sets. Y-STR polymorphisms in Central Portugal population, using YFiler, provide a powerful discrimination tool for routine forensic applications.
Assuntos
Cromossomos Humanos Y , Genética Populacional , Haplótipos , Sequências de Repetição em Tandem , Impressões Digitais de DNA , Frequência do Gene , Humanos , Masculino , Reação em Cadeia da Polimerase , PortugalRESUMO
The Y-chromosome haplotypes defined by nine STRs (DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392 and DYS393) were studied in 207 unrelated individuals from Central Portugal and 63 from Azores Islands. The most common haplotype in Central Portugal was shared by 3.4% of the males, while 160 haplotypes were unique. In Azores Islands the most common haplotype was shared by 6.4% of the males, while 40 haplotypes were unique. The values of haplotype diversity were 0.993 for Central Portugal and 0.976 for Azores Islands.