Analysis of Indian population based on Y-STRs reveals existence of male gene flow across different language groups.

A study of three different Y-specific microsatellites (Y-STRs) in the populations from Uttar Pradesh (UP), Bihar (BI), Punjab (PUNJ), and Bengal (WB), speaking modern indic dialects with its roots in Indo-Aryan language, and from South of India (SI), speaking the South Indian languages with their root in Dravidian language, has shown that the predominant alleles observed represent the whole range of allelic variation reported in different population groups globally. These results indicate that the Indian population is most diverse. The similarity between the allelic variants between the populations studied by others in Africa and Asia and in this study between WB, PUNJ, UP, BI, and SI are of interest. It demonstrates that these population groups, housed in eight states of the country in different geographic locations, broadly correspond with Indo-Aryan and Dravidian language families. Further, our analyses based on haplotype frequency of different marker loci and gene diversity reveals that none of the population groups have remained isolated from others. High levels of haplotype diversity exist in all the clusters of population. Nonsignificant results based on Markov chain steps and Slatkin's linearized genetic distances indicate that there has been migration to and from in these population groups. However, some of the marginally significant interpopulation differences could be attributed to one or more of the castes with high diversity embedded within the population groups studied. Haplotype sharing between populations, F(ST) statistics, and phylogenetic analysis identifies genetic relatedness to be more between individuals belonging to two different states of India, WB and PUNJ, followed by UP and BI, whereas SI branched out separately.