The 9-bp deletion between the mitochondrial lysine tRNA and COII genes in tribal populations of India

A 9-base-pair (bp) deletion located between the lysine tRNA (MTTK) and COII (MTCOX*2) genes in the human mitochondrial genome is a valuable marker for tracing population relationships. Previous research has shown that the 9-b p deletion is associated with two major clusters of control region sequence s; one occurs in sub-Saharan Africa, while the other is associated with Asi an populations and populations of Asian origin. We surveyed 898 individuals from 16 tribal populations in India and found 6 individuals with the 9-bp deletion. Sequences of the first hypervariable segment (HVI) of the mtDNA c ontrol region from these 9-bp deletion-bearing mtDNAs were compared to thos e previously reported from Asian and African populations. Phylogenetic anal ysis indicates three distinct clusters of tribal Indian 9-bp deletion mtDNA types. One cluster, found in northeast India, includes southeast Asian and Indonesian mtDNA types. The remaining two clusters appear to have unique o rigins in southern India. These data provide further evidence of past migra tions from Asia into the northeast corner of the Indian subcontinent.