Effects of MSTN Gene Knockout on Growth Performance and Muscle Transcriptome in Chinese Merino Sheep (Xinjiang Type)

The MSTN gene plays a critical role in muscle development, and its knockout has been shown to significantly enhance growth performance in animals. In this study, we utilized MSTN knockout Chinese Merino sheep (Xinjiang type), which were previously generated in our laboratory, to compare their growth performance, hematological, and biochemical parameters with those of a control group. The results revealed that the MSTN knockout sheep exhibited significantly improved traits, including body weight, body length, and body height, without adverse effects on blood or metabolic parameters. Transcriptomic analysis identified 121 differentially expressed genes (DEGs) involved in key pathways such as amino acid metabolism, muscle contraction, and immune response. A protein–protein interaction (PPI) network was constructed, highlighting 10 core genes that may play pivotal roles in the biological processes regulated by MSTN. RT-qPCR validation of several key genes confirmed the results of the transcriptomic analysis. This study provides both theoretical foundations and practical insights for gene-edited breeding in meat sheep.