牦牛ZP3基因的克隆及蛋白质结构的预测

Cloning of ZP3 Gene and Prediction of ZP3 Protein Structure in Yak

本研究对牦牛ZP3基因的编码区进行了克隆,在此基础上对ZP3蛋白的分子结构预测,为研究牦牛受精生物学提供基础。根据GenBank中普通牛的ZP3核苷酸序列设计特异性引物,以牦牛卵巢组织总RNA为模板,通过RT-PCR技术扩增牦牛ZP3基因cDNA序列(GenBank登录号为GQ856646),利用DNAMAN生物软件进行核苷酸和氨基酸序列分析、蛋白质专家系统ExPASy进行ZP3蛋白质分子结构预测。结果表明,扩增出的牦牛ZP3基因编码序列长1 266 bp,编码421个氨基酸。牦牛与牛、猪、狗、人、鼠和鸡ZP3基因核苷酸相应序列的同源性分别为98.42%、96.73%、79.67%、78.71%、69.15%和56.61%,氨基酸同源性分别为98.10%、83.85%、74.24%、70.26%、62.62%和46.12%,符合物种进化规律。预测的ZP3蛋白二级和三级结构显示它是一个具有22个氨基酸信号肽的亲水性β-桶状跨膜蛋白。牦牛ZP3基因编码区的成功克隆,为进一步研究该基因的结构与功能及其在受精过程中的作用提供了基础。

The objectives of this study were to clone the coding region of ZP3 gene and to predict ZP3 protein structure in order to provide a theoretical basis for the study of fertilization biology in the yak. The specific primers were designed according to reference se- quence of Bos taurus in GenBank. Using the total RNA extracted from yak ovarian tissue as template, eDNA sequence of ZP3 gene of yak was cloned by RT-PCR. The nucleotide and amino acid sequences were analyzed using DNAMAN software and the structure of ZP3 protein was predicted using ExPASy. The coding region of ZP3 gene in yak was 1 266 bp long and encoded 421 amino acids. Nucleotide sequence similarities of the ZP3 gene in yak compared to cattle, pig, dog, human, mouse and chicken were 98.42% , 96.73% , 79. 67% , 78.71% , 69.15% and 56.61% , respectively. Amino acid sequence similarities of the ZP3 protein in yak were 98.10% , 83.85% , 74.24% , 70.26% , 62.62% and 46.12% ,respectively,of those in cattle,pig,dog,human,mouse and chicken,which were in the evolutionary order of these species. The predicted secondary and tertiary structures showed that ZP3 protein was a hydrophilie transmembrane I^-barrel protein with a signal peptide of 22 amino acids. The coding region of ZP3 gene in yak was successfully cloned, which provides a theoretical basis for further study on its structure and function and its role in the fertilization process.