Mitochondrial DNA polymorphism in three Brazilian Indian tribes.

The first 360 base pairs of the mitochondrial DNA (mtDNA) major noncoding region from 82 individuals affiliated with the Brazilian Xavante, Zoró and Gavião tribes were sequenced. A total of 14 different lineages were observed, the largest number (8) being found among the Zoró. The latter share five lineages with the Gavião (who are their neighbors and are culturally similar to them), but only one with the Xavante. The lineages can be grouped into four clusters, previously identified by other authors. The 9 base pair deletion characteristic of Asian and Pacific populations occurs in 32% of the individuals, whose mtDNA was classified in five lineages, all grouped in one of the four clusters. Nucleotide diversity, as evaluated by three indices, are not much different from those observed in Indians from Central and North America, despite the fact that the Xavante consistently show lower numbers. These results do not confirm previous generalizations about the genetic diversity of Amerindians, and the need for additional studies in this system is stressed. © 1996 Wiley-Liss, Inc.