The Effect Of Feeding Conditions On MiRNAs Expression And Meat Quality Of Sunit Sheep

The 8 microRNAs(miR-1,miR-206,miR-128,miR-486,miR-133,miR-23a,miR-30a,miR-223)and RNA expression of prdml,sox6,TNNC1,Tnnt3,prox1 were analyzed by Real-Time PCR in Longissimus dorsi(B),Triceps brachii(Q),and Biceps femoris(H)of Sunite sheep from grazing and drylot feeding for 12 months old.The meat quality and the slaughter performance were measured.The correlationship between miRNAs expression,mRNA expression,meat quantity and slaughter performance was established.How miRNAs affects meat quality(color)at mRNA levels,miRNAs on meat quality(color)at mRNA level by fast twitch muscle genes(sox6,tnnt3)and slow twitch muscle genes(tnncl,prox1)was explored,as follows:Eight miRNAs were both expressed in grazing and drylot feeding Sunit sheep,and the grazing higher than drylot feeding.There were significant positive correlations between the two miRNAs,indicating that miRNAs formed a regulator network which played roles together.The Effect of feeding conditions on Meat Quality,The Growth traits,weight and Carcass weight of the grazing group was significantly higher than the drylot feeding group(p<0.05).Slaughter rate of the drylot feeding group was significantly higher than grazing group(P<0.05).The shearing force of the drylot feeding group in triceps brachii was significantly higher than the grazing group(p<0.05),The redness of the drylot feeding group in longissimus dorsi was significantly higher than the grazing group(_p<0.05),in triceps brachii the grazing group was significantly higher than the drylot feeding group(p<0.05).Under two feeding conditions,miR-1 were showed significantly positive correlation with meat weight.Positive correlation between miR-486 and weight.Indicating that the high expression of miR-land miR-486 could increase the production of Sunit sheep.Negative correlation between miR-30a and height and meat weight in the longissimus dorsi.Positive correlation between miR-133,miR-30a and the red value(a*)in longissimus dorsi.Negative correlation with lightness(L*)in triceps brachii.Negative correlation between miR-206 and pH value in longissimus dorsi and biceps femoris.Under two feeding conditions,the regulation mechanism of miRNA on meat quality(color),miR-30a decreased the mRNA expression of fast twitch muscle and slow twitch muscle gene,which was not significant.Suggested that the effect of miR-30a on color may have other regulatoiy mechanisms.