LncRNA IMFlnc1 promotes porcine intramuscular adipocyte differentiation by sponging miR-199a-5p to up-regulate CAV-1

Abstract

Background Local Chinese local pig breeds have better meat quality, such as thinner muscle fiber and higher intramuscular-fat (IMF) content. However, its molecular regulation mechanism has not been discussed in-depth. Studies indicated that long non coding RNAs (lncRNAs) participate in the regulation of muscle and fat development. The expressional differences of lncRNAs in the longissimus dorsi (LD) muscle were identified between Huainan pigs (local Chinese pigs, fat-type, HN) and Large White pigs (lean-type, LW) at 38, 58, and 78 days post conception (dpc).Results In total, 2131 novel lncRNAs were identified in 18 samples, and 291, 305, and 683 differentially expressed lncRNAs (DELs) were found between these two breeds at three stages, respectively. GO and KEGG analysis of the DEL co expressed mRNAs showed that muscle development and energy metabolism were more active at 58 dpc in HN, but at 78 dpc in LW pigs. Muscle cell differentiation and myofibril assembly might contribute to earlier myogenesis and primary-muscle-fiber assembly in HN, and cell proliferation, insulin, and the mitogen-activated protein kinase (MAPK) pathway might contribute to longer proliferation in LW pigs. The PI3K/Akt and cAMP pathways were associated with higher IMF deposition in HN. IMFlnc1 was selected for functional verification, and results indicated that it regulated the expressional level of caveolin-1 (CAV-1) as a competing endogenous RNA (ceRNA) for miR-199a-5p.Conclusion Our data contributed to understanding lncRNAs in porcine-muscle development and IMF deposition, and provided valuable information for improving pig-meat quality.