Study On The Muscle Fiber Composition And Expression Of Related Signalling Pathway Genes In Different Varieties Of Pigs

ObjectivesIn order to explore the gene expression patterns and interspecies differences of muscle fiber components and related signal pathways in different breeds of pigs,and to analyze the correlation between CFL2 and the key components of muscle fiber composition and signal pathway at the same time.Provide pre-work basis the detection method of pig muscle fiber traits.MethodsChoose the same paternal purebred He Bao pig,purebred Yorkshire,purebred Landrace and DYL hybrid(Duroc,Yorkshire,Landrace)crossbred product sow,respectively in 1d,30 d,60d,90 d,120d,150 d and 180 d sows with the same feeding conditions,each stage three sows,total of 84.The meat quality traits(muscle fiber diameter,shear force,meat color and p H)were measured at the time of slaughter and slaughter as usual.To detect expressions of muscle fiber composition longissimus muscle(My HCslow,My HC2 a,My HC2 x,My HC2 b,MLC,?-actin),signaling pathway critical component(MEF2C,sk MLCK,Rho A,AMPK?2,MAPKp38 and Ca M)And muscle fiber candidate gene CFL2 m RNA and protein by real-time quantitative PCR and Western blot.SPSS17.0 statistical software was utilized to analyze the variance of the data.Results1.Meat quality changes of He Bao pig,Yorkshire and Landrace are basically the same.With the growth of pigs,the flesh of purse,Yorkshire and Landrace sows were significantly enhanced,the shear strength was remarkably increased,muscle fiber diameter was significantly increased(P<0.05),different breeds of meat color and p H after 120 d has no significant difference,porcine shear no significant differences among varieties at 180 d,and muscle fiber diameter of Yorkshire and Landrace was significant different(P <0.05).2.The m RNA detection of each gene: the same gene in different pig breeds has roughly the same postnatal expression.But different varieties at the same time point there is a significant difference in the expression level.The contents of My HC and the m RNA expression of muscle fiber were similar in Yorkshire and Landrace,while the 60d-150 d of He Bao pig was significantly different from that of Yorkshire and Landrace(P<0.05).The expression of MEF2 C in different varieties of 1d-60 d was not significantly different,and the 90d-150 d He Bao pig was significantly higher than others,and 180 d He Bao pigs were significantly lower than other varieties.The expression of AMPK is increased with the increase of age.The expression of Rho A was significantly higher than that of other breeds(P<0.01).The expression of CAM in He Bao pig was significantly higher than that of other varieties.(P<0.01).3.The expression of protein by Western Blot: The expression of protein was consistent with each other.The difference was that the expression level was different.My HC SLOW of He Bao pig was overall significantly(P<0.01)than other species,other total My HC and muscle fiber component(My HC2 a,My HC2 x,My HC2 b,MLC,and ?-actin),Landrace overall significantly higher than other varieties(P<0.05),in addition to individual time points the difference was not significant.The expression of CFL2 protein in the He Bao pig was significantly higher than that of imported pigs(Yorkshire,Landrace and DYL hybrids)from birth to 180 days(P<0.01).The expression of sk MLCK protein in Landrace was significantly higher than that in other varieties(P<0.01),while that of He Bao pig was similar to that of Yorkshire.With the increase of pig age,expression of AMPK was decreased,while MAPK as a whole increased.The protein of Rho A,Yorkshire was significantly higher than other varieties(P<0.01)from birth to 150 d,only 180 d lower than the He Bao pig.The expression of CAM was similar to that of DYL hybrids pig,which was higher than that of Yorkshire and Landrace.4.The correlation analysis showed that all the fleshy traits were significantly correlated with age(P<0.01).Only my HC2 a was positively correlated with age(P<0.01).a-actin was significantly correlated with age(P <0.05).The signal pathway of AMPK?2 and MAPKp38 was significantly correlated with age(P<0.05).My HC2 b and My HC2 a were significantly correlated with p H24 and muscle fiber diameter(P<0.05).AMPK?2 was associated with all fleshy traits.MAPK and Ca M were only correlated with shear and muscle fiber diameters.The expression of CFL2 was positively correlated with My HC slow(P<0.01).The total amount of My HC was positively correlated with MLC(P<0.01).The key components of signalling pathways(MEF2C,sk MLCK,AMPK?2,MAPKp38,Rho A)were associated with low levels of muscle fiber composition i In addition to Ca M.Conclusions1.The meat fleshy traits and myosin My HC2 a were significantly positively correlated with age.2.The content of myosin in My HC2 b influences the p H of meat,My HC2 a content influence muscle fiber diameter.Chinese local pig-He Bao pig meat quality is better than imported,one of the reasons is that the He Bao pig's diameter of muscle fibers is smaller.3.The signaling pathway AMPK?2 is associated with all fleshy traits,and MAPKp38 and Ca M are only associated with low shear and muscle fiber diameters.4.CFL2 gene may be affecting the muscle fiber composition through the regulation of My HC slow,and promote muscle fiber type changes and then participate in the impact of meat quality traits.