ABSTRACT
Intramuscular fat (IMF) content in chickens significantly contributes to meat quality. The main objective of this study was to assess the expression of calcineurin (CaN) and Ca2+/calmodulin-dependent protein kinase (CaMK) in lipogenesis in chicken muscle. Chickens were slaughtered and sampled at 4, 8, and 16 weeks of age. IMF content and the expression of CaN subunits and CaMK isoforms were measured in the thigh muscle tissue. The results showed that the IMF contents were greater at 16 weeks compared with those at 4 and 8 weeks (p<0.05). Transcription of fatty acid synthase (FAS) and fatty acid translocase CD36 (FAT/CD36) mRNA significantly increased with age, from four to 16 weeks (p<0.05). The mRNA levels of CaN B and CaMK IV were significantly lower at 16 weeks than at four weeks (p<0.05), but CaMK II mRNA levels were significantly higher than at four weeks (p<0.05). In order to evaluate the role of CaMK and CaN in adipogenesis, SV cells were incubated in standard adipogenic medium for 24 h and treated with specific inhibitor of CaMK and CaN. The expressions of CCAAT/enhancer binding protein b (C/EBPb, sterol regulatory element-binding protein 1 (SREBP1), and peroxisome proliferation-activated receptor g (PPARγ) were dramatically enhanced by the CsA, CaN inhibitor (p<0.05). KN93, CaMK II inhibitor, dramatically repressed the expression of those lipogenic gene (p<0.05). These results indicated that CaN and CaMK had different effects on adipogenesis in the muscle of chickens.
Keywords:
Ca2+/calmodulin-dependent protein kinase; calcineurin; chicken; regulation.
