Regulation role of Alternative Splicing in physiologies characteriscs of different tissues/organs in pigs

Alternative splicing (AS) is an important post-transcriptional regulation that leads to transcriptome and proteome diversity. In this study, we performed a comprehensive AS profile in nine organs from Duroc (DR)(lean-type) and Luchuan (LC)(obese-type) pigs. Notably, 94,990 AS events (87% being novel) from 14,393 genes were identified. Of them, 80% of AS events were Skipped exon (SE) type. Functional enrichment analysis showed that genes with more than ten AS events are closely associated with organ-specific functions. The number of differentially alternative splice genes (DSG) between DR and LC pigs in the same organ ranged from 935 to 1655. We selected three DSGs including PYGM, MAPK11, and CAMK2B to validate by RT-PCR. Significantly, there were lowest and highest number of DSGs in subcutaneous adipose and the small intestine between two breeds, respectively. In addition, overlap analysis between DSG and differentially expressed genes (DEGs) showed that there were highest number of overlapped genes in heart (195) and skeletal muscle (138). The TNNT1, TNNT3 and PHGDH genes, which affect muscle development and metabolism, are highly expressed in these two tissues and undergo specific alternative splicing. In conclusion, our study provides novel insight into molecular regulation of different organ physiologies and phenotype difference between obese- and lean-type pigs. It is helpful not only for animal breeding, but also have important value for human biomedical research.