Y-chromosome and mitochondrial DNA polymorphisms in Indian populations

Y-chromosome polymorphism using short tandem repeat (STR) markers on 94 nor mal males belonging to the Brahmin and Kamma caste populations of Andhra Pr adesh, India, and Siddis, a migrant population from Africa, inhabiting Hyde rabad, India, revealed heterogeneity as indicated by network analysis. We h ave observed population-specific haplotypes and alleles. Analysis of Y-Alu polymorphism (YAP) in Siddis showed the presence of Alu insertion in 40% of the individuals. However, YAP insertion was not found in Brahmins and Kamm as. The dendrogram based on hypervariable region I (HVR I) of the displacem ent loop (D-loop) sequence of mitochondrial DNA (mtDNA) of Siddis showed ge netic relationships to African populations. YAP and mtDNA analysis of Siddi s also confirmed their immigration from Africa.