The Expression Pattern Of MyHC Gene And Its Correlation With Meat Quality In Rongchang And Landrace Pigs

The objective of the current study was to compare four specific MyHC isoforms composition and express capability in longissimus and psoas muscle change at mRNA level of chinese local breed RongChang and Landrace pig.In addition to fiber typing slow-twitch and fast-twitch and count areas by immunocytochemistry,PHenotypic and specific fiber areas correlation analysis for meat quality was determined.The result as follows:The four specific MyHC isoforms mRNA expression and areas proportion of two fiber types is differenttly in breed and muscle.(1) compareing in breeds suggest that:The MyHCâ… mRNA expression is increased significantly in longissimus (P＜0.05) and psoas(P＜0.01) muscle of Rongchang pig,and MyHCâ…¡b fibres decreased significantly in both muscle(P＜0.01),MyHCâ…¡a expression has no Significant change in both muscle;MyHCâ…¡x expression increased significantly in psoas muscle of Landrace.For immunocytochemistry,In psoas muscle,Typeâ… fiberswere large in Rongchang than in Landrace,but have on Significant Differents in longissimus.(2) correlation analysis has show that:Muscle PH value,meat color,intramuscular fat were positively correlated with MyHCâ… ,shear strength and drip loss were negatively correlated with it,MyHCâ…¡a,â…¡x,â…¡b has oppositely effect.Especially,MyHCâ…¡have Significant effect in pH1(P＜0.05),intramuscular fat(P＜0.01),shear strength and drip loss(P＜0.01);For immunocytochemistry,muscle PH₁,PH₂meat color and intramuscular fat(P＜0.05) were postitively correlated with typeâ… fiber area;meat color/PH₁,intramuscular fat(P＜0.01) were negatively correlated with typeâ…¡fiber area,shear strength and drip loss(P＜0.01) were negatively correlated with typeâ…¡.