Multiple origins of Tibetan Y chromosomes

Abstract

The genetic origin of Tibetans was investigated using Y chromosome markers. A total of three populations were studied, two from central Tibet speaking central Tibetan and one from Yunnan speaking Kham. Two dominant paternal lineages (>80%) were identified in all three populations with one possibly from central Asia (YAP+) and the other from east Asia (M122C). We conclude that Tibetan Y chromosomes may have been derived from two different gene pools, given the virtual absence of M122C in central Asia and YAP+ in east Asia, with drift an unlikely mechanism accounting for these observations.

Genetic structures of the Tibetans and the Deng people in the Himalayas viewed from autosomal STRs

“…9,65,68 Other studies suggested that the high frequency of the Y Alu insertion (YAP) in the Tibetan population signals a significant genetic contribution from Central Asia. 8 Our result of NJ tree showed that Tibetan populations formed a distinctive cluster in the range of East Asians, not close to the Northeast or Southeast Asians but populations located closely beside the Tibetan Plateau; for example, Salar, Bai and Drung. However, the MDS plot showed that the Tibetans were quite close to the Altaic populations from North Asia, consistent with some of the previous studies.…”

“…Previous studies using classical genetic traits, 3 autosomal microsatellite markers 4,5 and mitochondrial DNA 6 suggest a North Asian origin of Tibetans, while evidences from the Y chromosomal Alu insertion (YAP) marker reveal much more intricate stories for the origin of Tibetan peoples. [7][8][9][10] Not like the Tibetan studies, genetic study on Deng population is totally absent in literature to date, and nothing is known about their origin. Therefore, a genetic study of Deng and comparative analyses with the relevant populations, including Luoba, Tibetans and other East Asians, may shed light on the origin of the Himalayan unique populations.…”

Genetic insights into the origins of Tibeto-Burman populations in the Himalayas

“…More than half of the Tibetan men possess the YAP polymorphic Alu insertion in their Y-chromosome which is believed to have originated in Central Asia, 1,4,11,14 although its source remains highly debated. 64,68,69 In this study, however, given the lack of representative Central Asian populations due to the paucity of the data available from the region, no clear connections were made between Tibet and its possible Central Asian genetic contributors.…”

“…On the other hand, previous Y-chromosome studies characterizing the Tibetan people 4,11,12 argue for Central Asian genetic contributions to account for the presence of Asian-specific YAP (Y Alu polymorphism) chromosomes (D-M174) in the plateau. Haplogroup D-M174 lineages are found at appreciable frequencies in the Andaman Islands of the Indian Ocean 13 but only minimally in all East Asian populations with the exception of Japan.…”

“…Haplogroup D-M174 lineages are found at appreciable frequencies in the Andaman Islands of the Indian Ocean 13 but only minimally in all East Asian populations with the exception of Japan. 1,4,11,12,14,15 Distinctive D-M174 subclades are observed in the Andaman Islands (D-M174*) and Japan (D2-M55), whereas Tibetans exhibit haplogroups D1-M15 and D3-P47.…”