Y Chromosome Haplotypes Reveal Distinct Migration Patterns in Siberia and the Americas. J.T. Lell, T.G. Schurr, R.I. Sukernik, Y.B. Starikovskaya, D.C. Wallace. Center for Molecular Medicine, Emory University, Atlanta, GA.

   Y chromosome haplotypes were analyzed for 533 individuals representing the native populations of the Americas and Siberia. A total of 112 distinct haplotypes (comprised of 7 biallelic markers and 4 microsatellites) were observed, and these haplotypes were further classified into haplogroups based on the the slower-evolving biallelic markers. Over 96% of the Native American Y chromosomes belonged to haplogroup A0 (defined by the M9 polymorphism) or A1 (M9/M3). Network analysis supported the conclusion that haplogroup A1 had a single origin during or immediately prior to initial entry into the New World. Additionally, the A0 haplotypes which probably gave rise to the A1 lineage were observed in the Chukchi, Kets, and Tuvans, in accordance with previous studies which traced the origin of this lineage to Central Siberia. Interestingly, a much more recently arisen lineage (A3), defined by the Tat polymorphism, was also shown to have its origin in Central Asia. The distribution of these lineages suggests that at least two major population expansion/migration events originated in the area of Lake Baikal, with the second event occurring after entry into the New World was blocked by glacial ice sheets. In contrast to the A1 lineage, a single origin for A0 in the Americas is not supported as discordance of A0 haplotypes was observed between North and South American natives. Nearyl 40% of the Siberian natives in this study did not harbor the ancient M9 polymorphism. The great majority of these individuals belonged to haplogroup B, defined by a polymorphism in the RPS4Y gene. Haplogroup B reached its highest frequencies in the native populations of Kamchatka and the Lower Amur and was also observed in a single Navajo individual (and at significant frequency in the Cheyenne and Tanana by Karafet et al. AJHG 64:817-931). We propose that the initial New World peopling event brought haplogroup A0 and A1 types from Beringia by way of Central Siberia, and that a later event contributed haplogroup B and distinct A0 types by way of a migration involving populations ancestral to the modern inhabitants of Kamchatka and the Lower Amur.