Transcriptome-Based Identification of the Muscle Tissue-Specific Expression Gene CKM and Its Regulation of Proliferation, Apoptosis and Differentiation in Chicken Primary Myoblasts

SIMPLE SUMMARY: The study of skeletal muscle growth and development has historically been viewed as an entry point and as a breakthrough event in the improvement of animal breeding in the livestock industry. Muscle is the major constituent of any meat product, and its growth performance and the resulting product quality are the core foci of modern breeding. In this study, we found that creatine kinase M-type-like (CKM) was specifically highly expressed in chicken muscle tissue. The quantitative real-time PCR (qPCR) results were consistent with the sequencing results. By overexpressing CKM and interfering with CKM expression in chicken primary myoblasts, we found that CKM could inhibit the proliferation and promote the apoptosis and differentiation of chicken primary myoblasts. Moreover, the transcriptome sequencing results after interference with CKM expression indicated that CKM is involved in chicken skeletal muscle development. These results suggest that CKM may play a crucial role in chicken muscle growth and development. ABSTRACT: Skeletal muscle is an essential tissue in meat-producing animals, and meat-producing traits have been a hot topic in chicken genetic breeding research. Current research shows that creatine kinase M-type-like (CKM) is one of the most abundant proteins in skeletal muscle and plays an important role in the growth and development of skeletal muscle, but its role in the development of chicken skeletal muscle is still unclear. Via RNA sequencing (RNA-seq), we found that CKM was highly expressed in chicken breast muscle tissue. In this study, the expression profile of CKM was examined by quantitative real-time PCR (qPCR), and overexpression and RNA interference techniques were used to explore the functions of CKM in the proliferation, apoptosis and differentiation of chicken primary myoblasts (CPMs). It was shown that CKM was specifically highly expressed in breast muscle and leg muscle and was highly expressed in stage 16 embryonic muscle, while CKM inhibited proliferation, promoted the apoptosis and differentiation of CPMs and was involved in regulating chicken myogenesis. Transcriptome sequencing was used to identify genes that were differentially expressed in CPMs after CKM disruption, and bioinformatics analysis showed that CKM was involved in regulating chicken myogenesis. In summary, CKM plays an important role in skeletal muscle development during chicken growth and development.