中山大学学报（自然科学版）2018，Vol.57Issue(1)：7-20,14.DOI:10.13471/j.cnki.acta.snus.2018.01.002
尼罗罗非鱼主要组织相容性复合体Ⅱβ(M HCⅡβ)基因的克隆、表达和多态性
Molecular cloning,expression and polymorphism analysis of major histocompatibility complex classⅡβgenes in Nile tilapia(Oreochromis niloticus)
摘要
Abstract
The major histocompatibility complex(MHC)classⅡβplay an important role in the immune response of teleost.In this study, full-length MHCⅡβcDNA and genomic sequences were obtained from Nile tilapia(Oreochromis niloticus)by rapid amplification of cDNA ends polymerase chain reaction (RACE-PCR).The full length of cDNA was 1 142 bp and the open reading frame(ORF)was 750 bp encoding 249 amino acid.The genomic structure of MHCⅡβgenes was similar with other teleost species including 5 exons and 4 introns.By homology comparison and phylogenetic analysis,MHCⅡβgenes of Nile tilapia had a higher identity and a closer evolutionary relationship with perciform fishes than other fi-shes.The putative protein had 30.6%~78.6%identity with those of other teleosts and mammals.Ten MHC Ⅱβalleles were obtained from the fifty positive clones of ORF from 25 individuals.The amino acid sequence analysis showed that polymorphism was mostly focused on exon 2.PCR-SSCP and sequencing results revealed one to six different alleles for two to twelve bands in susceptibile or resistant fishes that after Streptococcus iniae challenge, which suggested there were at least 3 loci.qPCR indicated that high expression of MHC Ⅱβwas detected in gill, heart, spleen, and lower expression in kidney, muscle, brain and the lowest expression in skin,intestine and liver.After Streptococcus iniae challenge,the ex-pression presented the tendency of the down-up-down in head and kidney,which demonstrated MHCⅡβ involved in tilapia immune response.关键词
尼罗罗非鱼/MHCⅡβ/组织分布/多态性Key words
Nile tilapia/MHCⅡβ/tissue expression/polymorphism分类
生物科学引用本文复制引用
何佳男,罗文娜,刘晓春,林浩然..尼罗罗非鱼主要组织相容性复合体Ⅱβ(M HCⅡβ)基因的克隆、表达和多态性[J].中山大学学报（自然科学版）,2018,57(1):7-20,14.基金项目
广东省海洋渔业科技推广专项(A201301B02) （A201301B02）
