齐口裂腹鱼MyD88基因的cDNA序列及特征分析

The cDNA sequence and characterization of myeloid differentiation factor 88 (MyD88) gene in Schizothorax prenanti

利用RT-PCR和RACE-PCR技术获得了齐口裂腹鱼（ Schizothorax prenanti） TLR信号转导途径中的关键接头分子MyD88基因cDNA全长序列，该序列共1479 bp，包括编码284个氨基酸残基的855 bp的开放阅读框，177 bp 5′非翻译区和447 bp 3′非翻译区，编码284个氨基酸。利用SMART软件分析，结果显示，该蛋白在N端和C端分别存在死亡结构域（Death domain， DD）和TIR结构域（Toll/IL-1 receptor homology domain， TIR）。齐口裂腹鱼MyD88氨基酸序列与鲤（ Cyprinus carpio）、斑马鱼（ Danio rerio）、大黄鱼（ Larimichthys crocea）、花鲈（ Lateolabrax japonicas）、虹鳟（ Oncorhynchus mykiss）的相似性为69.37％～91.90％，其中与斑马鱼的相似性最高。用 NJ 法构建的系统进化树中，齐口裂腹鱼MyD88和其它鱼类MyD88聚为一枝。

Prenant′s schizothoracin , Schizothorax prenanti （ Tchang ） , is one of the most important cold fish species in China, and it＆#39;s an important commercial fish distributed through upper reaches of the Yangtze River .The full-length cDNA of myeloid differentiation factor 88 （ MyD88 ） isolated by RT-PCR and RACE-PCR methods was 1479 bp, including an open reading frame （ ORF） of 855 bp encoding 284 amino acid residues , a 5′-terminal untranslated region （ UTR） of 177 bp, a 3′-terminal UTR of 447 bp.The MyD88 protein comprised a death domain on N terminal and a TIR domain on C terminal analysed by SMART program .The MyD88 amino acid sequence of S.prenanti had 69.37%~91.90% identity with Cyprinus carpio, Danio rerio, Larimichthys crocea, Lateolabrax japonicas, Oncorhynchus mykiss, and had the high-est similarity with D.rerio.Phylogenetic tree was constructed by neighbor-joining method which revealed that MyD 88 of S.prenanti was clustered with MyD 88 from other teleost fish reported previously .