摘要： 通过RT-PCR和RACE-PCR的方法,克隆了革胡子鲶生长激素基因全长cDNA,其长度为973 bp,包含一个03 bp的开放阅读框架(Open reading frame,ORF),59 bp的5′非编码区和311 bp的3′非编码区(含PolyA 尾25 bp).将革胡子鲶GH cDNA的ORF、5′非编码区和3′非编码区的序列分别与同为鲶形目印度囊鳃鲶、巨鲶鱼、南方鲶和鲶的上述序列进行比对分析,结果表明:革胡子鲶与上述鱼类生长激素ORF的核苷酸与氨基酸序列同源性较高,平均值分别为91.2%和9.4%,ORF区核苷酸的碱基替代类型表现出T/C转换的偏向性,平均值为44.5%,同时表现出转换/颠换偏差,平均值为2.381.5′和3′非编码区序列同源性平均值分别为75.4%和77.0%,保守性低于编码区.

关键词: 革胡子鲶, 生长激素, RACE, 全长cDNA, 序列分析

Abstract: In this study,the GHfull2length cDNA is cloned with the employment of RT2PCR and RACE2PCR techniques,which is 973 bp in length.The total length cDNA includes an open readingframe (ORF) of 603 bp,5′ UTRof 59 bp and 3′ UTR of 311 bp (Poly A of 25 bp included).Pairwise and multiple alignments of the sequences of ORF,5′ UTR,3′ UTR of Clarias gariepinus GH cDNA with those of Heteropneustes fossilis,Pangasianodon gigas,Silurus meridionalis and Silurus asotus are performed using DNAMAN 5.2.and MEG A 411 software.Sequence alignment analysis indicate that the average homologies are 91.% and 9614 % separately for ORF nucleotide and amino acid sequence between Clarias gariepinus and the 4 species of Siluriforms catfish mentioned above.ORF nucleotide substitution patterns represent the bias of transition between T and C and the average value is 44.5 %.Meanwhile,the base substitutions also show transition/ transversion bias and the average ratio reaches 2.381.5′ UTR and 3′ UTR nucleotide sequence homology are 7514 % and 7710 %,respectively,which are lower conservative than that of ORF nucleotide sequence.

Key words: Clarias gariepinus, Growth hormone, RACE, Full-length cDNA, Sequence analysis

中图分类号: 

• Q785