title: Evidence for balancing selection acting on KIR2DL4 genotypes in rhesus macaques of Indian origin.
abstract: The interaction of killer-cell immunoglobulin-like receptors (KIR) and their respective major histocompatibility complex (MHC) ligands can alter the activation state of the natural killer (NK) cell. In both humans and rhesus macaques, particular types of non-classical MHC class I molecules are predominantly expressed on the trophoblast. In humans, human leukocyte antigen G has been demonstrated to act as a ligand for KIR2DL4, present on all NK cells, whereas Mamu-AG may execute a similar function in rhesus macaques. During primate evolution, orthologues of KIR2DL4 appear to have been highly conserved, suggesting strong purifying selection. A cohort of 112 related and unrelated rhesus macaques of mostly Indian origin were selected to study their KIR2DL4 genes for the occurrence of polymorphism. Comparison of the proximal region provided evidence for strong conservative selection acting on the exons encoding the Ig domains. As is found in humans, in the Indian rhesus macaque population, two different KIR2DL4 entities are encountered, which differ for their intra-cellular signalling motifs. One genotype contains a complex mutation in the distal region of exon 9, which negates a serine/threonine kinase site. Furthermore, both allelic entities are present in a distribution, which suggests that balancing selection is operating on these two distinct forms of KIR2DL4.
authors.affiliation: Department of Comparative Genetics and Refinement, Biomedical Primate Research Centre, Lange Kleiweg 139, Rijswijk, 2288 GJ, The Netherlands. blokhuis@bprc.nl
authors.forename: Jeroen H
authors.initials: JH
authors.lastname: Blokhuis
authors.forename: Marit K
authors.initials: MK
authors.lastname: van der Wiel
authors.forename: Gaby G M
authors.initials: GG
authors.lastname: Doxiadis
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Bontrop
mesh_terms: D000483:Alleles; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D019143:Evolution, Molecular; D005091:Exons; D005828:Genetics, Population; D005838:Genotype; D006801:Humans; D055261:Immunogenetic Phenomena; D007194:India; D007694:Killer Cells, Natural / Q000276:immunology; D008253:Macaca mulatta / Q000235:genetics* / Q000276:immunology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D011110:Polymorphism, Genetic; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D054345:Receptors, KIR2DL4 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012641:Selection, Genetic; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013045:Species Specificity; D014162:Transfection
chemical_list: D017931:DNA Primers; C515079:KIR2DL4 protein, human; D054345:Receptors, KIR2DL4; D011994:Recombinant Proteins; D017346:Protein Serine-Threonine Kinases