Abstract
Background: The Indian peninsula provides a suitable region for examination of the demographic impact of migrations and invasions in historical times, because its complex recent history has involved the long-term residence of different populations with distinct geographical origins and their own particular cultural characteristics.
Aim: The aim of the present study was to analyse Y chromosome haplotypes in tribes from eastern and north-eastern India, which provided the necessary phylogeographic resolution.
Subjects and methods: A total of 32 Y-chromosome SNPs and 17 Y-STRs were genotyped in 607 males from nine populations (Munda, Birhor, Oraon, Paharia, Santhal, Ho, Lachung, Mech and Rajbanshi) residing in East and Northeastern India.
Results: Y-chromosomal analysis revealed high frequency of the O2a haplogroup in Austroasiatic tribes and high haplotype diversity within specific haplogroups demonstrating a lesser degree of admixture of these populations with neighbouring populations in eastern India. In addition, the presence of O3a haplogroups in Sino-Tibetan populations reflects the influx from Southeast Asia during the demographic expansion through the Northeastern corridor.
Conclusion: The study suggested that the majority of the male gene flow of Austroasiatic tribes occurred during the late Pleistocene period. The results suggest gene flow from Southeast Asia to Northeast India, albeit more significantly among Tibeto-Burman than Austroasiatic-speaking populations.
Acknowledgements
Suraksha Agrawal conceived and formulated the project and received a grant from DBT. SA, MB and FK designed the experiments, MB and FA conducted all the experiments and analysed the data. The paper was written by MB and SA.
We are indebted to the Department of Biotechnology, New Delhi for financial assistance. Special thanks and appreciation are extended to Dr Parshuram and Mr Nagmani for their help in blood samples collection from the sites. Minal Borkar is thankful to the Council of Scientific and Industrial Research (CSIR) for awarding a Senior Research Fellowship.
Declaration of Interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.