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

CLC Number: 

• Q78

• S823