Comparative genomic analysis of the major histocompatibility complex class I region in the teleost genus Oryzias
Comparative genomic analysis of the major histocompatibility complex class I region in the teleost genus Oryzias
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DOI：
10.1007/s00251-009-0371-1
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发表时间：
2009-04
期刊：
影响因子：
3.2
通讯作者：
R. B. Mehta;M. Nonaka;M. Nonaka
中科院分区：
文献类型：
--
作者：
R. B. Mehta;M. Nonaka;M. Nonaka
硬骨鱼类的主要组织相容性复合体（MHC）I类区域包含一个紧密的IA类基因簇和其他几个直接参与I类抗原呈递的基因。此外，蛋白酶体β亚基基因PSMB 8和PSMB 10的二分单倍型谱系（称为d-和N-谱系）存在于青鳉的这一区域。为了在核苷酸序列水平上了解OryziasMHC I类区的进化，我们对包含Oryziasluzonensis d-谱系和Oryziasdancena d-和N-谱系的MHC I类区的细菌人工染色体克隆进行了分析，并将这三个克隆的序列与已发表的Oryziasd-和N-谱系的序列进行了比较。latipes表明，除了IA类基因在拷贝数上表现出种属特异性差异外，这五个基因组区域编码基因的顺序和方向是完全保守的。PSMB 8和PSMB 10基因具有跨种二型性。PSMB 10、PSMB 8和IA类基因侧翼的其余区域在种间和种内水平上显示出高度的序列保守性。因此，在稻属MHC I类区域中存在明显不同的选择压力下的三种独立的进化模式。
The major histocompatibility complex (MHC) class I region of teleosts harbors a tight cluster of theclass IAgenes and several other genes directly involved in class I antigen presentation. Moreover, the dichotomous haplotypic lineages (termed d- and N- lineages) of the proteasome subunit beta genes,PSMB8andPSMB10, are present in this region of the medaka,Oryzias latipes. To understand the evolution of theOryziasMHC class I region at the nucleotide sequence level, we analyzed bacterial artificial chromosome clones covering the MHC class I region containing the d- lineage ofOryzias luzonensisand the d- and N- lineages ofOryzias dancena.Comparison among these three elucidated sequences and the published sequences of the d- and N- lineages ofO. latipesindicated that the order and orientation of the encoded genes were completely conserved among these five genomic regions, except for theclass IAgenes, which showed species-specific variation in copy number. ThePSMB8andPSMB10genes showed trans-species dimorphism. The remaining regions flanking thePSMB10,PSMB8, andclass IAgenes showed high degrees of sequence conservation at interspecies as well as intraspecies levels. Thus, the three independent evolutionary patterns under apparently distinctive selective pressures are recognized in theOryziasMHC class I region.