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.

在研究相关基因在骨骼肌发育中的作用以及对骨骼肌形成的影响的研究中，特别是在转基因牛的研究中，激活牛骨骼肌中的外源基因是必要的。此时，应选择骨骼肌特异性启动子以启动功能性外源基因。在这里，通过实时PCR发现钙蛋白酶3（CAPN3）在骨骼肌和骨骼肌细胞中高表达。接下来，对牛CAPN3启动子进行5'缺失分析，结果表明Q5（-495 / + 40）区域是牛CAPN3的核心启动子。CAPN3核心启动子中的关键调控位点（-465 / -453）与转录因子MyoD相关，后者是骨骼肌特异性转录因子。此外，MyoD和CAPN3的mRNA和蛋白表达水平在骨骼肌细胞分化过程中呈正相关。MyoD的过表达增强了牛CAPN3核心启动子的活性。核心启动子Q5（-495 / + 40）可以驱动骨骼肌细胞中的外源基因EGFP和脂肪特异性表达基因PPARγ。总之，我们的研究获得了牛骨骼肌特异性启动子，并为研究功能基因在骨骼肌生长和发育中的作用提供了基础。这也为研究CAPN3的转录调控机制提供了基础。核心启动子Q5（-495 / + 40）可以驱动骨骼肌细胞中的外源基因EGFP和脂肪特异性表达基因PPARγ。总之，我们的研究获得了牛骨骼肌特异性启动子，并为研究功能基因在骨骼肌生长和发育中的作用提供了基础。这也为研究CAPN3的转录调控机制提供了基础。核心启动子Q5（-495 / + 40）可以驱动骨骼肌细胞中的外源基因EGFP和脂肪特异性表达基因PPARγ。总之，我们的研究获得了牛骨骼肌特异性启动子，并为研究功能基因在骨骼肌生长和发育中的作用提供了基础。这也为研究CAPN3的转录调控机制提供了基础。