Genomic congruence of Indo-European speaking tribes of western India with Dravidian-speaking populations of southern India: A study of 20 autosomal DNA markers

Abstract

Background: Due to its geographic location, Gujarat has played a major role in assimilation of different cultures with those of the subcontinent of India and is home to a number of Indo-European speaking tribes.

Aim: This study examined the genetic structure and extent of gene differentiation in eight Indo-European speaking tribal populations of southern Gujarat in western India. It also determined if there was any residual effect of linguistic and cultural assimilation of Indo-European speaking groups on the genomic profile of the tribes under study.

Methods: Twenty autosomal DNA markers (Alu InDels and Restriction Fragment Length Polymorphisms) were analysed.

Results and conclusions: Average heterozygosity levels were high and degree of gene differentiation (G_ST = 2%) was small, indicating that genetic drift may not have played a major role in bringing out a characteristic genetic differentiation in these groups. The genetic structure of the populations revealed that neither of these groups was overtly admixed nor completely isolated. Other analyses undertaken on the population affiliations revealed only a slight influence of Indo-European speaking populations on the tribal groups of Gujarat, but there was an overwhelming influence of Dravidian speaking groups of southern India, suggesting that genetic affinities may not necessarily be dependent on linguistic similarities.

Keywords::

• Linguistic similarities
• genetic affinities
• heterozygosity
• AMOVA
• genetic drift

Acknowledgements

We want to thank all the individuals who volunteered to provide blood samples for this study on genetic variation. We would also like to extend our gratitude towards the Valsad Raktdan Kendra (Centre for blood donation, Valsad), Valsad, Gujarat for helping us in the collection of blood samples. We also wish to thank Department of Anthropology, University of Delhi, Delhi for granting us the ethical clearance necessary to get the grant from DBT, Delhi. While undertaking the study, we strictly complied with the ethical guidance of the committee.

Appendix I.  Allele frequencies at the 6 Alu InDel markers among the study populations and other tribal populations of India¹

Appendix II.  Allele frequencies at the 6 Alu InDel markers among the study populations, other Indian populations and Eurasian populations¹

Appendix III.  frequencies at the 6 Alu InDel markers among the study populations, Dravidian and Indo-European speaking populations of India and Indo-European speaking groups of Eurasia¹

Appendix IV.  Allele frequencies at 6 Alu InDel markers among the study populations, populations of south India and Eurasia¹

Declaration of interest: The authors wish to thank Department of Biotechnology (DBT), New Delhi for providing us the necessary grant (vide letter BT/PR9840/MED/12/366/2007) in support of the project. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.