Bovine CAPN3 core promoter initiates expression of foreign genes in skeletal muscle cells by MyoD transcriptional regulation.

Abstract

Activating foreign genes in bovine skeletal muscle is necessary in the study of the role of related genes in skeletal muscle development and the effects on skeletal muscle formation, especially in the study of transgenic cattle. At this time, a skeletal muscle-specific promoter should be selected to initiate a functional foreign gene. Here, calpain3 (CAPN3) was found to be highly expressed in skeletal muscle and skeletal muscle cells by real-time PCR. Next, 5' deletion analysis of the bovine CAPN3 promoter was performed and showed that Q5(-495/+40) region was the core promoter of the bovine CAPN3. A key regulatory site (-465/-453) in CAPN3 core promoter was associated with the transcription factor, MyoD, which is a skeletal muscle-specific transcription factor. Furthermore, the mRNA and protein expression levels of MyoD and CAPN3 were positively correlated during skeletal muscle cell differentiation. The overexpression of MyoD enhanced the activity of the bovine CAPN3 core promoter. The core promoter Q5(-495/+40) could drive the exogenous gene EGFP and the fat-specific expression gene PPARγ in skeletal muscle cells. In summary, our study obtained a bovine skeletal muscle-specific promoter and provided a basis for studying the role of functional genes in the growth and development of skeletal muscle. It also provides a basis for studying the transcriptional regulation mechanism of CAPN3.