Microsatellites provide evidence for Y chromosome diversity among the founders of the New World

Recently, Y chromosome markers have begun to be used to study Native Americ an origins, Available data have been interpreted as indicating that the col onizers of the Ne,New World carried a single founder haplotype, However, th ese early studies have been based on a few mostly complex polymorphisms of insufficient resolution to determine whether observed diversity stems from admixture or diversity among the colonizers. Because the interpretation of Y chromosomal variation in the New World depends on founding diversity, it is important to develop marker systems with finer resolution, Here we evalu ate the hypothesis of a single-founder Y haplotype for Amerinds by using 11 Y-specific markers in five Colombian Amerind populations, Two of these mar kers (DYS271, DYS287) are reliable indicators of admixture and detected thr ee non-Amerind chromosomes in our sample. Two other markers (DYS199, M19) a re single-nucleotide polymorphisms mostly restricted to Native Americans. T he relatedness of chromosomes defined by these two markers was evaluated by constructing haplotypes with seven microsatellite loci (DYS388 to 394), Th e microsatellite backgrounds found on the two haplogroups defined by marker DYS199 demonstrate the existence of at least two Amerind founder haplotype s, one of them (carrying allele DYS199 T) largely restricted to Native Amer icans. The estimated age and distribution of these haplogroups places them among the founders of the New World.