A genomic insight into the peopling of Manipur, India.

Introduction: manipur, one of the northeastern states of India, lies on the ancient silk route and serves as a meeting point between the Southeast Asia and South Asia.

Aims: this study was conducted to understand and estimate the genomic diversity among various population groups of Manipur, with a major goal of getting an insight into the peopling of India.

Methods: seven human-specific Alu insertion/deletion polymorphisms were screened on 366 individuals belonging to eight ethnic groups of Manipur, including both tribal (Aimol, Kabui, Kom, Paite, and Thadou) and nontribal populations (Bamon, Muslims, and Meitei).

Results: all the biallelic loci are polymorphic except CD4, which is monomorphic in six out of the eight studied populations. The average heterozygosity values are low (0.309-0.395), with relatively higher average heterozygosity values among Bamons and Muslims than other studied populations, suggesting admixture in these two populations. Lower heterozygosity values of the tribal populations place them closer to the Chinese and Southeast Asian populations, indicating their late arrival in India coupled with geographical isolation.

Conclusion: this study provides evidence for the genetic heterogeneity of the Manipur populations. It also supports the hypothesis, based on the archeological and linguistic findings, that the northeastern populations of India have a close genetic affinity with the southeastern and East Asian populations. The genetic discontinuity observed between the studied populations and the other non-Northeast Indian populations suggests the role of northeast border as a "barrier" rather than a corridor.