Identification of differentially expressed genes in longissimus dorsi muscle between Wei and Yorkshire pigs using RNA-sequencing

Intramuscular fat (IMF) content is an important trait closely correlated with meat quality, which is highly variable among swine breeds from diverse genetic backgrounds. In order to elucidate the molecular mechanism underlying porcine meat quality, we adopted RNA-sequencing to detect transcriptome in the longissimus dorsi muscle of Wei pigs (a Chinese indigenous breed) and Yorkshire pigs (a Western lean-type breed) with different IMF content. A total of 717 differentially expressed genes (DEGs) were identified in our study, with 323 up-regulated and 394 down-regulated genes in Wei pigs compared with Yorkshire pigs. GO analysis showed that DEGs significantly related to muscle proliferation and development, lipid storage and catabolic, extracellular matrix structural constituent, and neutral amino acid transmembrane transporter activity. Pathway analysis revealed that DEGs associated with fatty acid metabolism, steroid biosynthesis, glycerophospholipid metabolism, protein digestion and absorption, and amino acid metabolism. Quantitative real time PCR confirmed the differential expression of 11 selected DEGs from both pig breeds. The results provide useful information to investigate the transcriptional profiling in skeletal muscle of different pig breeds with divergent phenotypes, and several DEGs can be taken as functional candidate genes for affecting pork quality. Overall design: Transcriptome sequencing in longissimus dorsi muscle of Wei and Yorkshire pigs

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