Diversified genomic contribution among south Indian populations--a study on four endogamous groups of Andhra Pradesh

The present study examines genomic variation among three tribal (Nayakpod, Thoti and Kolam) and a caste (Niyogi Brahmin) population groups of Andhra Pradesh, south India.

The present study examined the genomic diversity of the populations in relation to other population groups of India using 20 autosomal loci.

A total of 204 blood samples from the population groups described above were collected and analysis was carried out following standard protocols.

All markers were found to be polymorphic in these groups except AluCD4 among Thotis. High average heterozygosity values (0.3927 among Thotis to 0.4268 among Brahmins) are comparable with the available autosomal (Alu and restriction site polymorphisms) data for the Nilgiri hill tribes of Tamil Nadu, south India. The gene differentiation value (Gst) was found to be 4.2. The principal coordinate analysis (PCO) based on data from the 20 markers presents a smaller cluster of presently studied populations than that of the Nilgiri hill tribes of Tamil Nadu, south India.

Although the presently studied populations of Andhra Pradesh have heterozygosity similar to that of Nilgiri hill populations, the former are more closely placed on the PCO plot than the latter, who are more scattered. Also the gene differentiation (Gst) of the former is much lower than that of the latter, indicating considerable regional variation in the inflow of genes from diverse ethnic groups within south India.