摘要： 旨在克隆牦牛Sirtuin7（SIRT7）基因，预测其蛋白结构和功能，并检测其mRNA在牦牛各组织和不同发情时期卵巢中的表达。采集成年牦牛（3~5岁）的肝脏、乳腺、大肠、肾等组织及处于卵泡期、红体期、黄体期的卵巢。提取各组织的总RNA，并通过反转录PCR（Reverse transcription PCR，RT-PCR）扩增获得牦牛SIRT7的基因序列。通过不同的生物信息学软件比对SIRT7基因的序列同源性、构建系统进化树以及预测牦牛SIRT7所编码蛋白的结构和功能。采用实时荧光定量PCR（Quantitative real-time PCR，qRT-PCR）方法检测SIRT7 mRNA在牦牛各组织和不同发情时期卵巢中的表达。结果显示，牦牛SIRT7基因的开放阅读框（Open reading frame，ORF）大小为1 203 bp，编码400个氨基酸。牦牛SIRT7基因的核苷酸序列与黄牛、绵羊、山羊的同源性较高。SIRT7蛋白为亲水性蛋白。二级结构由α-螺旋（47.4%）、β-折叠（29.7%）、β-转角（15.7%）及无规卷曲（7.2%）组成。磷酸化和糖基化分析结果表明，SIRT7蛋白有38个磷酸化位点，24个O-糖基化位点。荧光定量结果为，SIRT7 mRNA在牦牛的肾中表达最高。在牦牛卵巢中，卵泡期、红体期、黄体期SIRT7 mRNA的表达量呈持续升高的趋势，其中黄体期表达量最高。为揭示SIRT7在牦牛生长发育，尤其是卵巢发育过程中的调控作用提供一定的基础数据。

关键词: 牦牛, SIRT7, 克隆, 组织表达谱, 卵巢

Abstract: This research was aimed to clone the Sirtuin7 (SIRT7) gene in yak, predict the structure and function of SIRT7 protein, and detect its mRNA expression in different tissues and ovary during different phases of oestrus. The liver, breast, large intestine, kidney and ovaries in follicular phase, red body phase, and luteal phase from adult yaks(3-5 years) were collected. Total RNA of each tissue was extracted and the gene sequence of yak SIRT7 was amplified by reverse transcription PCR (RT-PCR). Different bioinformatics softwares were used to compare sequence homology of SIRT7 gene construct phylogenetic tree, and predict the structure and function of yak SIRT7 protein. The expressions of SIRT7 mRNA in different yak tissues and ovaries during different stages of oestrus were detected by quantitative real-time PCR (qRT-PCR). The result showed that the open reading frame (ORF) of yak SIRT7 was 1 203 bp, encoded 400 amino acids. The SIRT7 gene nucleotide sequence of yak was highly homologous to that of cattle, sheep, and goat. The SIRT7 protein was a hydrophilic protein. The secondary structure of SIRT7 protein was made of alpha helix(47.4%), beta fold(29.7%), beta turn(15.7%) and random coil(7.2%). Phosphorylation and glycosylation analysis showed that SIRT7 protein contained 38 phosphorylation sites and 24 O-glycosylation sites. Quantitative real-time PCR result showed that SIRT7 mRNA was highest expressed in the kidney of yak. In the yak ovary, the expression levels of SIRT7 mRNA increased gradually in follicular phase, red body phase and luteal phase.The highest expression level was found in luteal phase. This research provides some basic data for revealing the regulatory role of SIRT7 in the growth and development of yak, especially in the development of ovaries.

Key words: Yak, SIRT7, Clone, Tissue expression profile, Ovary

中图分类号: 

• Q78

• S823