title: Distinct diversity of KIR genes in three southern Indian populations: comparison with world populations revealed a link between KIR gene content and pre-historic human migrations.
abstract: By interacting with polymorphic HLA class I molecules, the killer cell immunoglobulin-like receptors (KIR) influence the innate and adaptive immune response to infection. The KIR family varies in gene content and sequence polymorphism, thereby, distinguishing individuals and populations. To investigate KIR diversity in the earliest settlers of India, we have characterized the KIR gene content in three Dravidian-speaking populations (Mollukurumba, Kanikar, and Paravar) from the state of Tamil Nadu, southern India. The activating KIR genes and putative group-B KIR haplotypes were frequent in Paravar and Kanikar, a scenario analogous to those seen previously in other populations of Indian origin, indicating that predominance of group-B KIR haplotypes is the characteristic feature of Indian populations. In contrast, the KIR gene profile of Mollukurumba was more related to Caucasian type. It is not clear whether a local-specific selection or a recent admixture from Iran is responsible for such discrete profile in Mollukurumba. Each southern Indian population had distinct KIR genotype profile. Comparative analyses with world populations revealed that group-B KIR haplotypes were frequent in the natives of India, Australia, and America, the populations associated with those involved in extensive prehistoric human migrations. Whether or not natural selection has acted to enrich group-B KIR haplotypes in these migratory descendants is an issue that requires objective testing.
authors: UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA 90095, USA. rrajalingam@mednet.ucla.edu
authors: Raja
authors: R
authors: Rajalingam
authors: Zeying
authors: Z
authors: Du
authors: Ashley
authors: A
authors: Meenagh
authors: Lihui
authors: L
authors: Luo
authors: Valampuri John
authors: VJ
authors: Kavitha
authors: Rajamanickam
authors: R
authors: Pavithra-Arulvani
authors: Arumugam
authors: A
authors: Vidhyalakshmi
authors: Surendra K
authors: SK
authors: Sharma
authors: Ivan
authors: I
authors: Balazs
authors: Elaine F
authors: EF
authors: Reed
authors: Ramasamy M
authors: RM
authors: Pitchappan
authors: Derek
authors: D
authors: Middleton
mesh_terms: D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes; D006801:Humans; D007194:India; D044469:Racial Groups / Q000235:genetics*; D054340:Receptors, KIR / Q000235:genetics*
chemical_list: D054340:Receptors, KIR