Population severance in manipur at dopamine receptor D2 locus

Area of Science:

• Population genetics
• Human migration studies
• Genomic diversity

Background:

• Northeast India's Tibeto-Burman populations exhibit significant genetic heterogeneity.
• Manipur, bordering Myanmar, is expected to be genetically diverse due to its numerous tribal and non-tribal groups.
• Previous studies utilized various genomic markers to explore the peopling of Northeast India.

Purpose of the Study:

• To investigate the peopling of Manipur using genetic markers.
• To analyze allele and haplotype frequencies of three sites (Taq1A, Taq1B, and Taq1D) on the dopamine receptor D2 (DRD2) gene.
• To understand the distribution patterns of DRD2 gene polymorphisms in Manipuri populations.

Main Methods:

• Collected blood samples from 367 individuals across eight populations in Manipur.
• Included three non-tribal groups (Meitei, Muslims, Bamon) and five tribal groups (Aimol, Kabui, Paite, Kom, Thadou).
• Examined polymorphism, allele and haplotype frequencies at three DRD2 gene sites.

Main Results:

• All three DRD2 gene sites (Taq1A, Taq1B, Taq1D) were polymorphic in all studied populations.
• Relatively low heterozygosities were observed, indicating genetic discontinuity between Northeast India and mainland India.
• Results suggest that eastward migration from Africa through India is unlikely.

Conclusions:

• High genetic heterogeneity and the prevalence of ancestral haplotype (B2D2A1) in the Meitei suggest admixture.
• This admixture likely involves incoming Mongoloid groups and an existing proto-Australoid element.
• The study underscores the genetic distinctiveness of Manipuri population groups concerning DRD2 gene polymorphism.