Abstract: 【Objective】 The aim of this study is to clone and analyze the 5′ regulatory region of myostatin gene in sheep and to investigate the effect of progesterone on the activity of the 5′ regulatory region. 【Method】 The 5′ regulatory region of myostatin gene in sheep was cloned by PCR, and the regulatory motifs and transcriptional factors, along the region or the similar regions of bovine and porcine, were analyzed and compared by some softwares such as MatInspector. The EGFP was selected as reporter gene and the expression vectors were constructed. The vector was transfected into C2C12 cells and the different doses of progesterone (0 nmol•L-1, 10 nmol•L-1, 100 nmol•L-1 and 1 000 nmol•L-1) were supplemented, then the mRNA of reporter gene EGFP or endogenous myostatin gene was detected by RT-PCR. 【Result】The 5′ regulatory region of myostatin gene in sheep was obtained, and two sites that is possibly contributive to double-muscular character were predicted. Many putative regulatory motifs and transcriptional factors, which may play important roles in the transcriptional regulation of myostatin gene, were found along the regulatory region of sheep, bovine and porcine, such as E-box, MEF2, MTATA, MTBF, HOMF, PRE, ARE and GRE. Most of motifs were found in three animals, but the bases, positions and numbers of the motifs were different among the three animals. The expression vectors pMSTN5’Regu-EGFP of sheep were successfully constructed and transfected. 100 nM progesterone obviously inhibited the mRNA of reporter gene EGFP and endogenous myostatin gene. 【Conclusion】The transcription of myostatin gene in sheep was regulated by various transcriptional factors and corresponding regulatory motifs, and the appropriate dose of progesterone inhibited the transcription of myostatin gene by downregulating the activity of the myostatin gene 5′ regulatory region.  

Key words: sheep, Myostatin gene 5&prime, regulatory region, bioinformatic analysis, regulatory motif, transcriptional factor, progesterone