title: Sequence polymorphism and evolution of three cetacean MHC genes.
abstract: Sequence variability at three major histocompatibility complex (MHC) genes (DQB, DRA, and MHC-I) of cetaceans was investigated in order to get an overall understanding of cetacean MHC evolution. Little sequence variation was detected at the DRA locus, while extensive and considerable variability were found at the MHC-I and DQB loci. Phylogenetic reconstruction and sequence comparison revealed extensive sharing of identical MHC alleles among different species at the three MHC loci examined. Comparisons of phylogenetic trees for these MHC loci with the trees reconstructed only based on non-PBR sites revealed that allelic similarity/identity possibly reflected common ancestry and were not due to adaptive convergence. At the same time, trans-species evolution was also evidenced that the allelic diversity of the three MHC loci clearly pre-dated species divergence events according to the relaxed molecular clock. It may be the forces of balancing selection acting to maintain the high sequence variability and identical alleles in trans-specific manner at the MHC-I and DQB loci.
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, China.
authors.forename: Shi Xia
authors.initials: SX
authors.lastname: Xu
authors.forename: Wen Hua
authors.initials: WH
authors.lastname: Ren
authors.forename: Shu Zhen
authors.initials: SZ
authors.lastname: Li
authors.forename: Fu Wen
authors.initials: FW
authors.lastname: Wei
authors.forename: Kai Ya
authors.initials: KY
authors.lastname: Zhou
authors.forename: Guang
authors.initials: G
authors.lastname: Yang
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002591:Cetacea / Q000235:genetics*; D019143:Evolution, Molecular; D006649:Histocompatibility Antigens / Q000737:chemistry / Q000235:genetics; D016013:Likelihood Functions; D008285:Major Histocompatibility Complex / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012641:Selection, Genetic
chemical_list: D006649:Histocompatibility Antigens
references.citation: Immunogenetics. 1989;29(1):19-24
references.pmid: 2562799
references.citation: Mol Ecol. 2007 Oct;16(19):4051-65
references.pmid: 17727623
references.citation: J Hered. 2000 Jul-Aug;91(4):279-82
references.pmid: 10912673
references.citation: Genetics. 2003 Jul;164(3):1229-36
references.pmid: 12871927
references.citation: Immunogenetics. 2006 Jul;58(7):542-58
references.pmid: 16791623
references.citation: Mol Biol Evol. 1999 May;16(5):611-8
references.pmid: 10335654
references.citation: Immunogenetics. 1998 Sep;48(4):242-52
references.pmid: 9716643
references.citation: Zoolog Sci. 2006 Feb;23(2):147-53
references.pmid: 16603807
references.citation: J Evol Biol. 2003 May;16(3):363-77
references.pmid: 14635837
references.citation: Mol Biol Evol. 2005 Apr;22(4):1107-18
references.pmid: 15689528
references.citation: Bioinformatics. 1998;14(9):817-8
references.pmid: 9918953
references.citation: Mol Biol Evol. 1995 Jul;12(4):582-93
references.pmid: 7659014
references.citation: Mol Phylogenet Evol. 2008 Apr;47(1):36-44
references.pmid: 18328734
references.citation: Immunogenetics. 2007 Jul;59(7):581-92
references.pmid: 17486336
references.citation: Mol Biol Evol. 1994 Sep;11(5):725-36
references.pmid: 7968486
references.citation: J Mol Evol. 2008 Apr;66(4):384-94
references.pmid: 18347751
references.citation: Anim Genet. 1994 Jun;25(3):165-72
references.pmid: 7943950
references.citation: Immunogenetics. 2001 Aug;53(6):490-500
references.pmid: 11685460
references.citation: Annu Rev Immunol. 1993;11:269-95
references.pmid: 8476562
references.citation: Genetics. 1990 Apr;124(4):967-78
references.pmid: 2323559
references.citation: Nature. 1993 Jul 1;364(6432):33-9
references.pmid: 8316295
references.citation: Evolution. 2003 Aug;57(8):1707-22
references.pmid: 14503614
references.citation: Immunogenetics. 1998 Sep;48(4):266-72
references.pmid: 9716646
references.citation: Tissue Antigens. 2001 Jul;58(1):1-8
references.pmid: 11580849
references.citation: J Hered. 2005 Jul-Aug;96(4):310-7
references.pmid: 15843636
references.citation: Mol Biol Evol. 2007 Aug;24(8):1586-91
references.pmid: 17483113
references.citation: Immunogenetics. 1994;39(5):355-8
references.pmid: 8168853
references.citation: Genetics. 2000 May;155(1):431-49
references.pmid: 10790415
references.citation: Bioinformatics. 2003 Aug 12;19(12):1572-4
references.pmid: 12912839
references.citation: Immunogenetics. 1999 Oct;49(11-12):919-30
references.pmid: 10501834
references.citation: Mol Biol Evol. 2007 Aug;24(8):1596-9
references.pmid: 17488738
references.citation: Immunogenetics. 2007 Dec;59(12):937-48
references.pmid: 18049818
references.citation: Nature. 1987 Oct 8-14;329(6139):506-12
references.pmid: 3309677
references.citation: Nature. 1977 May 19;267(5608):275-6
references.pmid: 865622
references.citation: Mol Ecol. 2007 Feb;16(3):531-40
references.pmid: 17257111
references.citation: Immunogenetics. 2006 May;58(4):283-96
references.pmid: 16568262
references.citation: BMC Evol Biol. 2009 Jan 25;9:20
references.pmid: 19166626
references.citation: Proc Natl Acad Sci U S A. 1993 Aug 15;90(16):7480-4
references.pmid: 8356042
references.citation: Immunogenetics. 2000 Mar;51(3):169-78
references.pmid: 10752625
references.citation: Immunogenetics. 2004 Apr;56(1):12-27
references.pmid: 14997355
references.citation: Proc Natl Acad Sci U S A. 2005 May 31;102(22):7922-7
references.pmid: 15894616
references.citation: Nucleic Acids Res. 1997 Dec 15;25(24):4876-82
references.pmid: 9396791
references.citation: J Vet Med Sci. 1998 Oct;60(10):1093-6
references.pmid: 9819762
references.citation: Immunogenetics. 2006 Oct;58(10):805-16
references.pmid: 17021859