RESUMO
New frequencies for the beta-globin gene cluster haplotypes are presented for the Aché (N = 82 individuals), Guarani (N = 76), and Kaingang (N = 54), three Native South American populations that live in an area between parallels 20 degrees S and 30 degrees S not covered by previous studies at this locus. The haplotype frequencies obtained for the three populations are within the interval observed for 28 other Native American populations. The Aché show much less haplotypes (five) than the other two populations (9-10), the haplotype prevalences being more similar to those of the Guarani than to the Kaingang. The Native American total heterozygosity was about half (0.41) that obtained for the African populations (0.71), but was not much different from those obtained for other continents. A geographical pattern was disclosed in South America by mapping the frequencies of the most common haplotype (haplotype 2), and by means of spatial correlation analysis. The analysis of molecular variance (AMOVA) and pairwise F(ST) data suggest three distinct sectors for the genetic landscape of Native South America: the Andes, the Center/Southeast region, and the Amazon.
Assuntos
Globinas/genética , Indígenas Norte-Americanos/genética , Família Multigênica , Frequência do Gene , Geografia , Haplótipos , Heterozigoto , Humanos , Indígenas Norte-Americanos/classificação , FilogeniaRESUMO
A total of 1037 individuals living in five different sociogeographic regions of Brazil were studied in relation to 12 short tandem repeat polymorphisms. The objective was to assess the degree of European, African, and Amerindian contributions to their gene pools. Although most of the genetic variability was found within regions, significant differences were also observed between regions. The estimated relative proportions of the above-indicated continental contributions showed intermediate values between those obtained with uniparental (mtDNA, Y-chromosome) data, and a higher percentage of European heritage as compared to previous autosome results. A north-south trend of increasing European contribution was also found, in agreement with the history of the Brazilian population.