西农萨能奶山羊gBTN1A1基因的筛选、克隆及序列分析

利用抑制消减杂交技术研究同一只西农萨能奶山羊泌乳中期和末期的乳腺组织差异表达基因,以泌乳中期乳腺cD-NA为测试组,末期乳腺cDNA为驱动组,构建消减文库,得到山羊(Capra hircus)嗜乳脂蛋白基因的部分序列。根据牛(Bos)和绵羊(Ovisaries L.)基因组序列进行电子拼接,并设计引物,得到山羊嗜乳脂蛋白基因的CDs区全序列,应用RT-PCR技术从山羊乳腺组织总RNA中扩增克隆了山羊嗜乳脂蛋白基因CDs区,命名为gBTN1A1,并登录GenBank(EF102891)。gBTN1A1基因开放读码框由1581个碱基组成,编码526个氨基酸,前26个氨基酸为推定的信号肽区域。gBTN1A1基因核苷酸序列与牛(NM-174508)、人(NM-001732)和鼠(AK145168)的同源性分别为97%、88%和84%,氨基酸序列的同源性分别为96%、84%和70%。其二级结构、跨膜区域及信号肽分析均与牛、人和鼠的BTN1A1基因相似。

Screening, Cloning and Sequence Analysis of gBTN1A1 Gene in Xinong Saanen Dairy Goat

The mammary glands in middle and late stages of lactation of the Xinong Saanen dairy goat were chosen to isolate differentially expressed genes,and a forward suppression subtractive hybridization(SSH)cDNA library was constructed.SSH was performed from cDNA of driver(mammary gland in late lactation stage)and tester(mammary gland in middle lactation stage).The partial sequence of goat(Capra hircus)butyrophilin gene was screened from subtracted cDNA library of differentially expressed genes.The cDNA of goat butyrophilin gene was amplified and cloned from total RNA of goat mammary gland by RT-PCR,named as gBTN1A1,and registered in GenBank(GenBank accession No.EF102891).gBTN1A1 gene with an ORF of 1 581 nucleotides encoded a polypeptide of 526 amino acids with a putative signal peptide of 26 amino acids.The nucleotide sequence homology of gBTN1A1 of Xinong Saanen dairy goat was found to be 97%,88% and 84% compared with that of bovine(NM-174508),human(NM-001732)and mouse(AK145168),while the amino acid sequence homology to be 96%,84% and 70%,respectively.The secondary structure,transmembrane domain and signal peptide of gBTN1A1 gene were similar with the compartments of bovine,human and mouse.