水产学报2012，Vol.36Issue(8)：1167-1178,12.DOI:10.3724/SP.J.1231.2012.27903
尼罗罗非鱼MHC ⅡA基因的克隆、表达及多态性分析
Molecular cloning, expression and polymorphism analysis of major histocompatibility complex (MHC) class Ⅱ A of Nile tilapia (Oreochromis niloticus)
摘要
Abstract
The major histocompatibility complex (MHC) class Ⅱ A gene plays an important role in the immune response of teleost. In this study, the full length of MHC ⅡA cDNA and genomic sequences were obtained from healthy Oreochromis niloticus by homology cloning and rapid amplification of cDNA ends polymerase chain reaction (RACE-PCR). The full-length of cDNA sequence (Orni-DBA*0101, GenBank No: JF719813) comprises 1 205 bp with a 720 bp open reading frame (ORF) encoding a predicted protein with 239 amino acid residues. The genomic sequence was further identified to be 1 388 bp in length, which contains four exons and three introns. Eight class IIA alleles were identified from four healthy O. niloticus individuals. The variability that existed in the α-1 region was higher than that of half-smooth tongue sole. All the characteristic domains present in MHC IIA of other species could be found in O. niloticus MHC IIA sequence, including a leader peptide, two extracellular domains, a transmembrane region, and a cytoplas-mic domain. In addition, there are four conserved cysteine residues and abundant phosphorylation sites. The deduced amino acid sequence shares 23% - 65% identity with those of other vertebrates. Semi-quantitative reverse transcriptase PCR (RT-PCR) demonstrated that O. niloticus MHC IIA mRNA was ubiquitously expressed in all tested tissues, which is highly expressed in spleen, kidney, gills, liver, heart, gonad and gut, however, lowly expressed in muscle and bladder. Challenge of O. niloticus with pathogenic bacteria, Aeromonas hydrophila, results in a significant change of the expression of MHC IIA in the liver, spleen, kidney, gills and intestine. The result implied that MHC ⅡA might play an important role in the immune system.关键词
尼罗罗非鱼/表达/多态性/基因/克隆/MHCKey words
Oreochromis niloticus/ expression/ polymorphism/ gene/ cloning/ major histocompatibility complex (MHC)分类
生物科学引用本文复制引用
周芬娜,董忠典,李同明,傅咏,王慧..尼罗罗非鱼MHC ⅡA基因的克隆、表达及多态性分析[J].水产学报,2012,36(8):1167-1178,12.基金项目
中国博士后创新基金项目(20100481295) （20100481295）
山东省自然科学基金(ZR2009DQ021, Y2008D32) （ZR2009DQ021, Y2008D32）
山东省博士后创新基金项目(200703044) （200703044）
国家重大专项科技计划项目(2001BA804A29) （2001BA804A29）
