牦牛生长激素基因分子特性分析  

Molecular characteristics of growth hormone gene in yak

作　　者：王磊[1] 吴建平[1] 杨联[1] 张利平[1] 徐建峰[1] 方翟[1] 

机构地区：[1]甘肃农业大学动物科学技术学院,甘肃兰州730070

出　　处：《甘肃农业大学学报》2009年第6期1-7,共7页Journal of Gansu Agricultural University

基　　金：甘肃省科技攻关项目(2GS042-A41-001-04);教育部春晖计划项目(S2004-1-62021)

摘　　要：设计特异性引物,利用RT-PCR方法从牦牛脑垂体中扩增出生长激素基因(YGH)编码区全序列,并进行分子特性分析.结果表明:牦牛生长激素基因编码区全长654 bp,包含一个完整的阅读框,编码217个氨基酸.采用生物信息学方法对分子特性进行分析表明:动物生长激素基因在进化上非常保守,牦牛生长激素基因氨基酸序列与黄牛、山羊、绵羊、马、猪、猫和犬的同源性分别为100%、99.1%、98.6%、88.9%8、8.5%、88.9%和89.4%.牦牛生长激素蛋白有2个明显的疏水区域,存在2个强跨膜区和信号肽,是一种分泌型蛋白质,二级结构主要以α-螺旋和不规则卷曲为主,三级结构包含第28-215位氨基酸残基;牦牛生长激素蛋白有较高的抗原指数和抗原表位,这与YGH编码蛋白具有良好的抗原性相一致.Growth hormone is a single-chain polypeptide hormone and secreted by anterior pituitary. GH exist in a wide variety of vertebrates, it can promote animal growth and development. The objective of this study was to clone the yak GH gene and do sequence analysis. A pair of specific PCR primers were designed for cloning the coding sequence of GH gene from pituitary tissue in yak. A fragment with 654 bp was got by RT-PCR amplifying, in which included a complete open reading frame and it encoded 217 amino acids（GeneBank accession No. EF154193）. Bioinformatics analysis of the molecular characteristics showed that the growth hormone gene was very conservative. Compared nucleotide sequence with cattle, there was only a base difference, which the 607th base was A in yak, but C in cattle, and this difference did not led to amino acid change, and both encoded Arg. The amino acids sequences of yak shared 100 %, 99. 1%, 98. 6 %, 88. 9 %, 88. 5 %, 88. 9 % and 89.4 %sequence similarity with cattle, goat, sheep, horse, pig, cat and dog respectively; the protein had two obvious hydrophobic region, existence of two strong trans- membrane region and signal peptide. The protein second structure main was α-helix and irregular curly and three-dimensional solution structure composed of 28-215 amino acids. Yak growth hormone protein had higher antigenic index and higher lymphocyte epitopes, which was consistent with of the higher antigenicity of YGH coding protein.

关 键 词：牦牛 生长激素基因 克隆 分子特性 

分 类 号：S823.85[农业科学—畜牧学]