珠江口3种鲸豚的MHC-I基因多态性研究  

Study of MHC-I polymorphism in three cetaceans from the Pearl River Estuary, China

作　　者：余新建[1,2,3,4] 张西阳 林文治[1,2,3,4] 周蕊莲[1,2,3,4] 吴玉萍[1,2,3,4] 

机构地区：[1]南海生物资源开发与利用协同创新中心,广东珠海519082 [2]广东省海洋资源与近岸工程重点实验室,广东珠海519082 [3]珠海市海洋生物资源与环境重点实验室,广东珠海519082 [4]中山大学海洋科学学院,广东珠海519082

出　　处：《海洋科学》2016年第10期126-133,共8页Marine Sciences

基　　金：国家自然科学基金项目(41276147;41576128);农业部中华白海豚保护行动计划(2015);香港海洋公园保育基金(2013)~~

摘　　要：旨在了解珠江口栖息的中华白海豚(Sousa chinensis)、宽脊江豚(Neophocaena phocaenoides)和点斑原海豚(Stenella attenuate)免疫相关基因MHC-I(Major Histocompatibility Complex)的多态性及其表达情况,以期为这3种鲸豚的保育工作提供基础资料。通过克隆测序的方法,首次证实MHC-I基因在这3种鲸豚体内表达。选择压力分析,表明MHC-I基因在这3种鲸豚中均受到强烈的正选择作用,提示其具有重要的免疫功能。3种鲸豚的MHC-I基因在系统发育树上相互混杂在一起,表明MHC-I基因存在跨物种多态性。结合选择压力分析和跨物种多态性,发现MHC-I基因受到平衡选择作用。珠江口3种鲸豚MHC-I基因多态性可能由平衡选择维持。To gain the basic knowledge about cetacean conservation, we assessed the polymorphism and expression of the immunologic gene MHC-I（Major Histocompatibility Complex class I） in three cetaceans（Sousa chinensis, Neophocaena phocaenoides, and Stenella attenuata） around the Pearl River Estuary. We first confirmed the expression of MHC-I genes in the three cetaceans by cloning and sequencing. After selection pressure analysis, we found that relatively strong positive selections have acted on MHC-I genes in these three cetaceans, suggesting their important immunologic function. Phylogenetic analysis showed that the MHC-I genes of the three cetaceans did not cluster to three branches according to species but were mixed up, which implies the existence of trans-species polymorphism（TSP）. Together with the results of selection pressure analysis and TSP, we suggest that intense balancing selection has acted on MHC-I genes in these three cetaceans, which further maintained the polymorphism of MHC-I genes.

关 键 词：鲸豚 MHC(Major HISTOCOMPATIBILITY Complex) 表达 平衡选择 

分 类 号：Q953[生物学—动物学]