title: Positive selection of Toll-like receptor 2 polymorphisms in two closely related old world monkey species, rhesus and Japanese macaques.
abstract: Toll-like receptor 2 (TLR2) plays an important role in the recognition of a variety of pathogenic microbes. In the present study, we compared polymorphisms of TLR2 locus in two closely related old world monkey species, rhesus monkey (Macaca mulatta) and Japanese monkey (Macaca fuscata). By nucleotide sequencing of the third exon of TLR2 gene from 21 to 35 respective individuals, we could assign 17 haplotype combinations of 17 coding SNPs of ten non-synonymous and seven synonymous substitutions. A non-synonymous substitution at codon position 326 appeared to be differentially fixed in each species, asparagine for M. mulatta whereas tyrosine for M. fuscata, and may contribute to certain functional properties because it locates in the region contributing to ligand binding and interaction with dimerization partner of TLR2-TLR1 heterodimeric complex. Although TLR2 alleles have diverged to similar extent in both species, they have evolved in significantly different ways; TLR2 of M. fuscata has undergone purifying selection while the membrane-proximal part of the extracellular domain of M. mulatta TLR2 exhibits higher rates of non-synonymous substitutions, indicating a trace of Darwinian positive selection.
authors: Department of Immunogenetics, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
authors: Akiko
authors: A
authors: Takaki
authors: Akiko
authors: A
authors: Yamazaki
authors: Tomoyuki
authors: T
authors: Maekawa
authors: Hiroki
authors: H
authors: Shibata
authors: Kenji
authors: K
authors: Hirayama
authors: Akinori
authors: A
authors: Kimura
authors: Hirohisa
authors: H
authors: Hirai
authors: Michio
authors: M
authors: Yasunami
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D019143:Evolution, Molecular; D057809:HEK293 Cells; D006801:Humans; D008251:Macaca / Q000235:genetics*; D008253:Macaca mulatta / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D012641:Selection, Genetic; D016415:Sequence Alignment; D051195:Toll-Like Receptor 2 / Q000737:chemistry / Q000235:genetics*
chemical_list: D051195:Toll-Like Receptor 2