Mitochondrial and Y-chromosome diversity of the Tharus (Nepal): a reservoir of genetic variation

摘要: Central Asia and the Indian subcontinent represent an area considered as a source reservoir for human genetic diversity, with many markers taking root here, most of which are ancestral state eastern western haplogroups, while others local. Between these two regions, Terai (Nepal) is pivotal passageway allowing, in different times, multiple population interactions, although because its highly malarial environment, it was scarcely inhabited until few decades ago, when malaria eradicated. One oldest largest indigenous people represented by resistant Tharus, whose gene pool could still retain traces ancient complex interactions. Until now, however, investigations on their structure have been scarce mainly identifying East Asian signatures. High-resolution analyses mitochondrial-DNA (including 34 complete sequences) Y-chromosome (67 SNPs 12 STRs) variations carried out 173 Tharus (two groups from one Eastern Terai), 104 Indians (Hindus New Delhi tribals Andhra Pradesh) allowed identification three principal components: Asian, West Eurasian Indian, last including both local inter-regional sub-components, at least Y chromosome. Although remarkable quantitative qualitative differences appear among various also between sexes within same group, lineages shared or derived thus revealing deep ancestry Indians. Interestingly, component observed Andhra-Pradesh present all Tharu groups, whereas strongly prevails Hindu samples other Nepalese populations. The sequencing mtDNAs unresolved haplogroups provided informative that greatly improved mtDNA phylogeny relationships Malaysia, Andaman Islands Japan well India North Africa. Overall, this study gives paradigmatic example importance isolates variants not easily detectable general population.