Abstract
This study aims to explore the functional role of Myoz2 in myoblast differentiation, and elucidate the potential factors interact with Myoz2 in promoter transcriptional regulation. The temporal-spatial expression results showed that the bovine Myoz2 gene was highest expressed in longissimus dorsi, and in individual growth stages and myoblast differentiation stages. Knockdown of Myoz2 inhibited the differentiation of myoblast, and negative effect of MyoD, MyoG, MyH and MEF2A expression on mRNA levels. Subsequently, the promoter region of bovine Myoz2 gene with 1.7 Kb sequence was extracted, and then it was set as eight series of deleted fragments, which were ligated into pGL3-basic to detect core promoter regions of Myoz2 gene in myoblasts and myotubes. Transcription factors MyoD and MyoG were identified as important cis-acting elements in the core promoter region (−159/+1). Also, it was highly conserved in different species based on dual-luciferase analysis and multiple sequence alignment analysis, respectively. Furthermore, a chromatin immunoprecipitation (ChIP) analysis combined with site-directed mutation and siRNA interference and overexpression confirmed that the combination of MyoD and MyoG occurred in region −159/+1, and played an important role in the regulation of bovine Myoz2 gene. These findings explored the regulatory network mechanism of Myoz2 gene during the development of bovine skeletal muscle.
•Bovine Myoz2 was highly expressed in the longissimus thoracis and differentiated myoblast.•Myoz2 knock-down inhibits the differentiation of myoblasts.•The core promoter of bovine Myoz2 was located within the region −159/+1 relative to the TSS.•MEF2A and MyoG bind to the promoter of Myoz2, and interacted Myoz2 with in a regulatory network.