The Study Of FoxO1 And Genes Of Muscle Fiber Specification And Its Effect On Meat Quality In Sheep

The RNA expression of CnAa, NFATc3, MEF2c and protein level of FoxO1 were analyzed by Real-Time PCR and enzyme-linked immunosorbent assay(ELISA) in longissimus dorsi (B), triceps brachii (Q), and biceps femoris (H) in 32 Sunite and 32 Bamei sheep of 5,6,8,12 months old. The meat quality traits like shearing force, pH(pH(pH0、PH24) and color was measured. At mRNA level, the correlationship was established between CnAa, NFATc3, MEF2c, FoxO1 and MyHCs. Moreover, the correlationship between CnAa, NFATc3, MEF2c mRNA expression and meat quality was explored. The effect on meat quality by FoxO1 protein level was also investigated.The results showed that similar law of tissue-specific was found between CnAa, NFATc3, MEF2c, FoxO1 and MyHCs, which was expression in triceps brachii always higher than longissimus dorsi. In triceps brachii and biceps femoris of Sunite sheep, the expression of FoxOl showed positive correlation with NFATc3, MEF2c and showed negative correlation with MyHCI. In longissimus dorsi and triceps brachii of Sunite sheep, MEF2c showed positive correlation with MyHCIIa, MyHCIIb and MyHCIIx. There was positive correlation between CnAa, NFATc3 and MEF2c in Sunite sheep. Meanwhile, in longissimus dorsi and triceps brachii of Bamei sheep, the negative correlation showed between CnAa, NFATc3, MEF2c and FoxO1, MyHCI. The expression of CnAa always had positive correlation with NFATc3 in Bamei sheep.As to the relationship with meat quality, CnAa, NFATc3 and MEF2c all showed positive correlation with shearing force in longissimus dorsi and triceps brachii of Sunite sheep. Negative correlation between CnAa and pH, NFATc3 and color was found. In addition, to Bamei sheep, CnAa had negative correlation with shearing force. CnAa had negative correlation with pH24 and showed significant in biceps femoris (p<0.05). The expression of MEF2c had positive correlation with shearing force and PH24. NFATc3 had negative correlation with lightness(L*).As to the FoxO1 protein expression level, the trend in three tissues was consistent and showed the lowest level at 8 months old of Sunite sheep. FoxO1 protein expression level in biceps femoris were significant higher than other two tissues (p<0.05) at 5 months old. To Sunite sheep, FoxO1 protein expression showed positive correlation with mRNA expression. FoxOl protein expression level showed the lowest level at 12 months old of Bamei sheep, which had a reverse trend to Sunite sheep. FoxO1 protein expression level in biceps femoris showed significant higher than other two parts (p<0.05). FoxO1 protein expression showed positive correlation with mRNA expression in longissimus dorsi of Bamei sheep. Furthermore, Negative correlation between FoxO1 protein expression and shearing force, positive correlation between FoxO1 protein expression and pH24, lightness(L*) was found in two breeds.