Different population histories of the Mundari- and Mon-Khmer-speaking Austro-Asiatic tribes inferred from the mtDNA 9-bp deletion/insertion polymorphism in Indian populations.
Length variation in the human mtDNA intergenic region between the cytochrome oxidase II (COII) and tRNA lysine (tRNA(lys)) genes has been widely studied in world populations. Specifically, Austronesian populations of the Pacific and Austro-Asiatic populations of southeast Asia most frequently carry the 9-bp deletion in that region implying their shared common ancestry in haplogroup B. Furthermore, multiple independent origins of the 9-bp deletion at the background of other mtDNA haplogroups has been shown in populations of Africa, Europe, Australia, and India. We have analyzed 3293 Indian individuals belonging to 58 populations, representing different caste, tribal, and religious groups, for the length variation in the 9-bp motif. The 9-bp deletion (one copy) and insertion (three copies) alleles were observed in 2.51% (2.15% deletion and 0.36% insertion) of the individuals. The maximum frequency of the deletion (45.8%) was observed in the Nicobarese in association with the haplogroup B5a D-loop motif that is common throughout southeast Asia. The low polymorphism in the D-loop sequence of the Nicobarese B5a samples suggests their recent origin and a founder effect, probably involving migration from southeast Asia. Interestingly, none of the 302 (except one Munda sample, which has 9-bp insertion) from Mundari-speaking Austro-Asiatic populations from the Indian mainland showed the length polymorphism of the 9-bp motif, pointing either to their independent origin from the Mon-Khmeric-speaking Nicobarese or to an extensive admixture with neighboring Indo-European-speaking populations. Consistent with previous reports, the Indo-European and Dravidic populations of India showed low frequency of the 9-bp deletion/insertion. More than 18 independent origins of the deletion or insertion mutation could be inferred in the phylogenetic analysis of the D-loop sequences.
Thangaraj
Kumarasamy
K
Centre for Cellular and Molecular biology, Uppal Road, Hyderabad, 500 007, India.
Sridhar
Vempati
V
Kivisild
Toomas
T
Reddy
Alla G
AG
Chaubey
Gyaneshwer
G
Singh
Vijay Kumar
VK
Kaur
Suminder
S
Agarawal
Pooja
P
Rai
Amit
A
Gupta
Jalaj
J
Mallick
Chandana Basu
CB
Kumar
Niraj
N
Velavan
Thrimulaisamy P
TP
Suganthan
Rajanbabu
R
Udaykumar
Divi
D
Kumar
Rashmi
R
Mishra
Rachana
R
Khan
Arif
A
Annapurna
Chitikineni
C
Singh
Lalji
L
D001210:Asia, Southeastern / Q000208:ethnology; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV / Q000235:genetics*; D005006:Ethnicity / Q000235:genetics; D006801:Humans; D007194:India; D011110:Polymorphism, Genetic; D044382:Population Groups / Q000235:genetics; D012357:RNA, Transfer, Lys / Q000235:genetics*; D017384:Sequence Deletion
D004272:DNA, Mitochondrial; D012357:RNA, Transfer, Lys; C117108:cytochrome C oxidase subunit II; D003576:Electron Transport Complex IV