MHC class II beta sequence diversity in the deer mouse (Peromyscus maniculatus): implications for models of balancing selection.
We studied population polymorphism at a major histocompatibility complex (MHC) class II beta gene in the deer mouse (Peromyscus maniculatus). We found that: (i) a single population of P. maniculatus has significantly higher levels of DNA and protein sequence diversity than worldwide samples from homologous genes in other taxa, including humans and mice; and (ii) the genealogy of allelic sequences in P. maniculatus deviates significantly from theoretical expectation under a model of symmetric balancing selection, in that alleles are relatively more divergent than expected. We suggest that the observation of high levels of pairwise allelic sequence divergence and deviation of the genealogy from theoretical expectation in P. maniculatus together provide support for a divergent allele advantage model for the maintenance of MHC polymorphism.
Richman
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AD
Plant Sciences Department, MSU Bozeman, Bozeman, MT 59719, USA, Department of Zoology, Universidad Nacional Autónoma de México, Instituto de Biología, México, México. arichman@montana.edu
Herrera
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LG
Nash
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D
D000483:Alleles; D000818:Animals; D001483:Base Sequence; D002140:California; D018076:DNA, Complementary / Q000737:chemistry; D019143:Evolution, Molecular; D005802:Genes, MHC Class II / Q000235:genetics*; D014644:Genetic Variation; D008800:Mexico; D008969:Molecular Sequence Data; D010542:Peromyscus / Q000235:genetics* / Q000276:immunology; D010802:Phylogeny; D011110:Polymorphism, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA
D018076:DNA, Complementary