10个半滑舌鳎家系MHC ⅡB基因多态性初步研究  

Polymorphisms and balancing selection in the half-smooth tongue sole, Cynoglossus semilaevis

作　　者：牛宝珍[1] 杜民[1] 陈松林[2] 

机构地区：[1]红河学院云南省高校农作物优质高效栽培与安全控制重点实验室,云南蒙自661199 [2]中国水产科学研究院黄海水产研究所农业部海洋渔业可持续发展重点开放实验室,山东青岛266071

出　　处：《海洋科学》2015年第12期70-76,共7页Marine Sciences

基　　金：国家自然科学基金资助项目(31360638);云南省教育厅科学研究基金重大专项项目(ZD2013009);云南省中青年学术和技术带头人后备人才资助项目(2015HB059);红河学院中青年学术带头人后备人才资助项目(2014HB0203);红河学院硕博资助项目(14bs11)

摘　　要：为检测10个半滑舌鳎(Cynoglossus semilaevis)家系MHCⅡB(Cyse-DAB)基因的多态性水平、MHCⅡ类B位点数目以及平衡选择的作用,作者利用多聚酶链式反应(PCR)和直接测序的方法对10个半滑舌鳎家系MHCⅡB基因位点遗传变异和平衡选择进行了研究。用特异性引物和PCR扩增的半滑舌鳎MHCⅡB基因片段大约397 bp,包含一部分第一外显子,全部第一内含子和全部第二外显子。10个半滑舌鳎家系中,每家系选取5个体,每个体5个克隆序列分析发现60个不同序列,代表60个等位基因,其中有28个是新发现的,已提交到Gen Bank。同源分析表明60个等位基因相似性为89.36%。共50个个体中,有6个存在5个不同等位基因,表明在半滑舌鳎至少存在3个座位。有9个家系的MHCⅡB序列多肽结合区(PBR)的非同义替换(dN)显著高于同义替换(dS)。In order to detect the polymorphism, number of alleles, and equilibrium selection of the MHC II B（Cyse-DAB） gene ofthe half smooth tongue sole, Cynoglossus semilaevis, we measured the genetic variation and balancing selection at MHC IIB loci in 10 half-smooth tongue sole by polymorphism chain reaction and the direct sequence method. We cloned and sequenced a 397 bp fragment of the MHC class IIB exon2. An amplified fragment spanned the partial exon1, complete intron1, and exon2. Five clones and five fry per individual（n = 50, 10 groups） were selected for MHC IIB sequence analysis. A total of 60 sequences were discovered which revealed 60 alleles, 28 of which were first found in this study and have been submitted to Genbank. The homology similarity was 89.36% among the sixty sequences. Five distinct sequences were presented in each of six individuals which denoted that there were at least three loci in half-smooth tongue sole MHC class IIB genes. Non-synonymous（dN） substitution was significantly higher than synonymous（dS） in the peptide-binding region of the MHC IIB gene in nine of the ten half-smooth tongue sole groups.

关 键 词：半滑舌鳎(Cynoglossus semilaevis) 多态性 MHCⅡB 平衡选择 

分 类 号：S917.4[农业科学—水产科学]