Characterization of ancestral and derived Y-chromosome haplotypes of new world native populations

We analyze the allelic polymorphisms in seven Y-specific microsatellite loc i and a Y-specific alphoid system with 27 variants (alpha h I-XXVII), in a total of 89 Y chromosomes carrying the DYS199T allele and belonging to popu lations representing Amerindian and Na-Dene linguistic groups. Since there are no indications of recurrence for the DYS199C-->T transition, it is assu med that all DYS199T haplotypes derive from a single individual in whom the C-->T mutation occurred for the first time. We identified both the ancestr al founder haplotype, OA, of the DYS199T lineage and seven derived haplogro ups diverging from the ancestral one by one to seven mutational steps. The OA haplotype (5.7% of Native American chromosomes) had the following consti tution: DYS199T, alpha h II, DYS19/13, DYS389a/10, DYS389b/27, DYS390/24, D YS391/10, DYS392/14, and DYS393/13 (microsatellite alleles are indicated as number of repeats). We analyzed the Y-specific microsatellite mutation rat e in 1,743 father-son transmissions, and we pooled our data with data in th e literature, to obtain an average mutation rate of .0012. We estimated tha t the OA haplotype has an average age-of 22,770 years (minimum 13,500 years , maximum 58,700 years). Since the DYS199T allele is found with high freque ncy in Native American chromosomes, we propose that 0A is one of the most p revalent founder paternal lineages of New World aborigines.