New Insight into the Role of the Leucine Aminopeptidase 3 () in Cell Proliferation and Myogenic Differentiation in Sheep Embryonic Myoblasts

Previous genome-wide association studies (GWAS) have found that may have the potential function to impact sheep muscle development. In order to further explore whether expression has an important role in the development of sheep embryonic myoblasts, we conducted the spatiotemporal expression profile analysis of at the tissue and cellular level. Then we used small interfering RNA and eukaryotic recombinant vectors to perform gain/loss-of-function analysis of . CCK-8 detection, EdU staining, and flow cytometry were used to investigate the impact of knockdown or overexpression on the proliferation of embryonic myoblasts. In addition, cell phenotype observation, MyHC indirect immunofluorescence, and quantitative detection of the expression changes of myogenic regulatory factors (MRFs) were used to explore the effect of on myogenic differentiation. The results showed that the expression level in muscle tissue of fetuses was significantly higher than that in newborn lambs and adult sheep, and its expression level on day 3 of differentiation was also significantly higher than that in the proliferation phase and other differentiation time points. silencing could significantly increase cell viability and EdU-positive cells, as well as prolonging the length of S phase of myoblasts to promote proliferation, while the results were reversed when was overexpressed. Moreover, silencing significantly hindered myotube formation and down-regulated the expression levels of MRFs from day 5 to day 7 of terminal differentiation, while the results were reversed when was highly expressed. Overall, our results suggested that the expression of impacts on the development of sheep embryonic myoblasts which provides an important theoretical basis for molecular breeding of meat production in sheep.