Heterogeneity of Y chromosome markers among Brazilian Amerindians

The allele frequency distribution of DYS19 and DYS199 loci were analyzed in 59 Brazilian Amerindians from five tribes from the Amazon region (Zoe, Awa -Guaja, Urubu-Kaapor, Katuena, and Kayapo, Xikrin of Bacaja village). Three different alleles of the DYS19 microsatellite (182-bp, 186-bp, and 190-bp) were found at average frequencies of 0.08, 0.85, and 0.07, respectively. T he DYS199-T allele was identified in 78% of the Amerindians studied (43/55) , the frequencies varying from 0.46-0.93. Four different haplotypes were fo und, the combination DYS19-186/DYS199-T being the most common (average freq uency of 0.65), followed by DYS19-186/DYS199-C with an average frequency of 0.22. These four haplotypes have been found in five other Brazilian tribes , and most of them were also identified in Native populations from South, C entral and North America. The observed variability at the DYS19 microsatell ite is probably due to forward or back mutations from the putative ancestra l 186-bp allele, since the mutation rate of this locus is high and the post -Columbian admixture of the Brazilian tribes studied is very low or undetec table to explain these data. On the other hand, the DYS19/DYS199 haplotype distribution may suggest that the two most common haplotypes (186-bp/T and 186-bp/C) were present among the population(s) that peopled the New World. (C) 1999 Wiley-Liss, Inc.