title: Patterns of reticulate evolution for the classical class I and II HLA loci.
abstract: Some alleles of the major histocompatibility complex (MHC) genes have a reticulate pattern of evolution, probably resulting from the exchange of segments by gene conversion or recombination. Here we compare the extent and patterns of reticulate evolution among the classical class I and class II loci of the human MHC using the recently developed compatibility and partition matrix methods. A complex pattern is revealed with substantial differences among loci in the extent and pattern of reticulation. Extremely high levels of reticulation are observed at HLA-B and HLA-DPB1, high levels at HLA-A and HLA-DRB1, moderate levels at HLA-C and HLA-DQB1, and low levels at HLA-DQA1. The reticulate events are concentrated in the exons encoding the highly variable, peptide-binding domains, suggesting that the sequence combinations produced by these events are maintained by natural selection.
authors.affiliation: Human Genetics Group, John Curtin School of Medical Research, The Australian National University, Canberra, ACT-0200, Australia.
authors.forename: I B
authors.initials: IB
authors.lastname: Jakobsen
authors.forename: S R
authors.initials: SR
authors.lastname: Wilson
authors.forename: S
authors.initials: S
authors.lastname: Easteal
mesh_terms: D000483:Alleles; D019295:Computational Biology; D019143:Evolution, Molecular; D005785:Gene Conversion; D005805:Genes, MHC Class I / Q000235:genetics*; D006681:HLA-D Antigens / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D011995:Recombination, Genetic; D017386:Sequence Homology, Amino Acid
chemical_list: D006681:HLA-D Antigens