溯河洄游型刀鲚MHCⅡβ基因克隆的初步研究  

Preliminary study on molecular cloning of MHCⅡβ gene of anadromous Coilia nasus

作　　者：轩中亚 姜涛[2] 刘洪波[2] 陈修报[2] 杨健[1,2] XUAN Zhongya;JIANG Tao;LIU Hongbo;CHEN Xiubao;YANG Jian(Wuxi Fisheries College, Nanjing Agricultural University, Wuxi Jiangsu 214081, China;Key Laboratory of Fishery Ecological Environment Assessment and Research Conservation in Middle and Lower Reaches of the Yangtze River, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi Jiangsu 214081, China)

机构地区：[1]南京农业大学无锡渔业学院,江苏无锡214081 [2]中国水产科学研究院淡水渔业研究中心,中国水产科学研究院长江中下游渔业生态环境评价与资源养护重点实验室,江苏无锡214081

出　　处：《海洋渔业》2022年第2期178-186,共9页Marine Fisheries

基　　金：农业农村部农业财政专项(CJDC-2017-22);中央级公益性科研院所(中国水产科学研究院级)基本科研业务费专项(2018GH14);江苏省自然科学青年基金项目(BK20160204)。

摘　　要：主要组织相容性复合体(major histocompatibility complex,MHC)是脊椎动物中高度多态的基因家族,其编码的蛋白质是适应性免疫的重要组件,其中MHCⅡβ基因表达的蛋白主要参与外源性抗体的呈递,与生物抗性及生态适应性具有重要关系。使用RACE技术首次克隆了溯河洄游型刀鲚(Coilia nasus)MHCⅡβ基因,全长为917 bp,开放阅读框的长度为765 bp,共编码254个氨基酸。通过同源性分析和分子系统进化分析发现,刀鲚MHCⅡβ氨基酸序列与其他硬骨鱼类和哺乳类的相似性在32.09%~71.79%,和鲱形目的鱼类同源性最高(71.79%)。研究结果可为溯河洄游型刀鲚MHCⅡ基因相关的多态性及生态适应等机制的研究提供理论基础。The major histocompatibility complex(MHC)is a highly polymorphic gene family in vertebrates.The protein encoded by it is an important component of adaptive immunity.Among the MHC family,the diversity of MHCⅡβgene has a close relationship with the natural selection that mediated by exogenous antigens(such as diseases and parasites).Therefore,MHCⅡβgene provides a good perspective for the investigation of local population adaptation and differentiation of migratory fish.The estuarine tapertail anchovy(Coilia nasus)is a small anadromous fish.However,recent studies have found that C.nasus has different ecotypes.There are anadromous,freshwater resident and landlocked ecotypes.Therefore,the countermeasures for diseases and parasites among these ecotypes should be completely different.Unfortunately,up to date,it still has been lack of understanding of whether MHCⅡβgenes of different ecotypes of C.nasus are diversified and different,as well as whether the genes are affected by natural selection.Exploring these scientific issues will be of great significance for clarifying the ecological adaptability and resistance characteristics for different corresponding types of diseases and parasites.In this study,we used rapid amplification of cDNA ends(RACE)technology to clone the MHCⅡβgene of anadromous C.nasus for the first time.The MHCⅡβgene of C.nasus showed a total length of 917 bp and an open reading frame of 765 bp,encoding a total of 254 amino acids.Through software analysis of DNAtools 6.0 and Clustal X 1.8,the secondary and tertiary structure of the protein encoded by C.nasus MHCⅡβgene was predicted.Results showed that the three-dimensional model of C.nasus MHCⅡβhad two different typical structural domains,indicating that C.nasus MHCⅡβprotein was similar to other fish in functions,e.g.,antigen presentation.By homology comparison and phylogenetic analysis,MHCⅡβgenes of C.nasus had the highest identity and the closest evolutionary relationship with Clupeiformes fish.The similarity between the MHC�

关 键 词：洄游型刀鲚 MHCⅡβ基因 CDNA全序列 生态抗性 生态适应性 

分 类 号：S917.4[农业科学—水产科学]