Y-chromosome SNP haplotypes suggest evidence of gene flow among caste, tribe, and the migrant Siddi populations of Andhra Pradesh, South India

Citation
Gv. Ramana et al., Y-chromosome SNP haplotypes suggest evidence of gene flow among caste, tribe, and the migrant Siddi populations of Andhra Pradesh, South India, EUR J HUM G, 9(9), 2001, pp. 695-700
Citations number
18
Categorie Soggetti
Molecular Biology & Genetics
Journal title
EUROPEAN JOURNAL OF HUMAN GENETICS
ISSN journal
10184813 → ACNP
Volume
9
Issue
9
Year of publication
2001
Pages
695 - 700
Database
ISI
SICI code
1018-4813(200109)9:9<695:YSHSEO>2.0.ZU;2-8
Abstract
From observations of lack of haplotype sharing based on Y-chromosome specif ic short tandem repeat (STR) loci, previous reports suggested negligible ge ne flow among different geographic populations of India. Using Single Nucle otide Polymorphism (SNP) sites in combination with STIRS, we observed evide nce of haplotype sharing across caste-tribe boundaries in South India. We e xamined 27 SNPs in the non-recombining region of the Y chromosome to invest igate gene flow in 204 individuals belonging to three caste groups (Vizag B rahmins, Peruru Brahmins, Kammas), three tribes (Bagata, Poroja, Valmiki) a nd an additional group (the Siddis) of African ancestry. Principal componen t and AMOVA analyses show that the between group component of variation is non-significant (P >0.05), while that among populations within the caste an d tribal groups is significant (P <0.001). In particular, the Valmikis and Siddis are close to the caste groups. Of a total of 11 distinct SNP-haploty pes observed, the two tribal groups (Bagata and Poroja) lack the haplotypes H4, H4A, H5A and H16, which are seen in the caste groups. In contrast, all three tribal groups exhibit the Southeast Asian haplotype H11 that is abse nt in the caste populations. The presence of haplotypes H4, H5, H14, and H1 6 in the Siddis indicate that they have assimilated considerable non-Africa n admixture. The evidence of haplotype sharing between castes and tribes is also found when the H14 lineage was further subdivided by five STR loci. W e conclude that even though these SNP-based Y-haplotypes are able to distin guish the populations, gene flow in these South Indian populations is not a s negligible as that inferred from other studies based on Y-specific short tandem repeat markers.