snRNA sequencing-based skeletal muscle analysis of Jiangquan black pigs with different average daily growth rates

The Jiangquan black pigs, a new breed of swine obtained by introducing traits from Duroc pigs into Yimeng black pigs, exhibits fast growth rates and high meat quality. To understand how daily weight gain influences muscle development in this breed, we analyzed longissimus dorsi muscle cell subpopulations from Jiangquan black pigs using snRNA and bulk RNA sequencing. Thirteen distinct cell types (e.g., muscle stem cells, satellite cells, fibroblasts) were identified, and marker genes (PAX7, MYOD, MYOG) were found to exhibit stage-specific expression during differentiation. Pseudotime analysis revealed the differentiation trajectories of these cell populations, while cell cycle analysis uncovered the higher mitotic activity in satellite cells of the fast-growth versus slow-growth groups. Furthermore, cell communication analysis highlighted the interactions between muscle cells and other cell types. Finally, intergroup analysis revealed that 2,466 and 2,597 genes were differentially expressed in muscle stem cells and muscle satellite cells, respectively. These genes were enriched in disease-related pathways. This study provides a single-cell resolution atlas of porcine muscle development, offering insights into the genetic regulation of growth and potential targets for breeding optimization.