Transcriptomic profiling of cardiac development in Bama Xiang pigs across key developmental stages.

Pigs have emerged as valuable large-animal models for cardiac xenotransplantation; however, the temporal dynamics of myocardial development in this species remains insufficiently defined. This study analyzed gene expression patterns across four key developmental stages (neonatal, juvenile, sexual maturity, and adulthood) to delineate the molecular mechanisms driving porcine myocardial development. Increases in heart weight were accompanied by proportional expansion of myocardial fiber area and chamber size, reflecting coordinated structural development. Transcriptomic profiling of myocardial tissue by RNA sequencing (RNA-seq) identified 2 189 differentially expressed genes (DEGs) across stage comparisons. Short time-series expression miner (STEM) analysis classified these DEGs into four major expression clusters enriched in pathways associated with myocardial development, immune responses, cell proliferation, and metabolic processes. Among 359 DEGs conserved across all developmental stages, six candidate genes were strongly associated with myocardial development. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) confirmed a significant correlation between the expression of these candidate genes and myocardial development in porcine tissue. These findings establish a transcriptomic framework for porcine myocardial maturation and provide a molecular basis for advancing cardiac xenotransplantation.