Comparison Of Meat Quality Related Characteristics Between Gushi Hens At 20 And 55 Weeks And Research Of The Basic Molecular Regulation

Meat of old Gu Shi hens are highly welcomed by the consumers in China for its good tastes and nutritional value.But its still undetermined that if there are difference between old and adult Gu Shi hens meat and,if there are,which genes these difference are regulated by.In order to comparing the skeletal muscle characteristics and analyzing the differentially expressed genes between Gu Shi hens at two different ages,this paper studied the difference between Gu Shi hens at 20 and 55 weeks by detecting the phenotype and the physical characters such as body measurements,carcass traits,meat quality and serum index.At the same time,finding the differentially expressed transcription between Gu Shi hens at 20 and 55 weeks by high-throughput transcriptome sequencing of breast muscle tissue in these two groups,and proceeding the Go and KEGG enrichment analysis of differentially expressed genes,trying to looking for the genes that specifically regulating skeletal muscle characteristics.The results of this study are as followed:1.The keel length,breast width,breast depth,hip width,Live weight,slaughter weight and width of intermuseular fat band of Gu Shi hens at 55 weeks were significantly higher than which at 20 weeks(P<0.05),percentage of half eviscerated yield,percentage of eviscerated yield of Gu Shi hens at 55 weeks were significantly lower than which at 20 weeks(P<0.05).Dressing percentage,breast and leg muscle percentage,abdominal fat percentage and subcutaneous fat depth were not significantly different between these two groups(P>0.05).2.For the breast muscle of Gu Shi hens,the drip loss,leucine content at 20 weeks were significantly higher than 55 weeks,intramuscular fat content,oleic acid content were significantly lower than 55 weeks(P<0.05).For the leg muscle of Gu Shi hens,The diameter of muscle fiber at 20 weeks were significantly lower than 55 weeks,the density of muscle fiber at 20 weeks were significantly higher than 55 weeks(P<0.05).Other meat quality index were not significantly different between these two groups(P>0.05).Triglycerides,high-density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C)in serum of Gu Shi hens at 55 weeks were significantly higher than which at 20 weeks(P<0.05).While total cholesterol were not significantly different between these two groups(P>0.05).3.Total 12216 genes were detected expressed in breast muscle tissue of Gu Shi hens at 20 and 55 weeks through high-throughput transcriptome,among which,there were 823 genes specially expressed in Gu Shi hens at 20 weeks,and 245 genes specially expressed in Gu Shi hens at 55 weeks.881 differentially expressed genes(DEGs)were detected,among which,there were 430 were highly expressed in breast muscle tissue of Gu Shi hens at 20 weeks,and 451 were highly expressed in Gu Shi hens at 55 weeks.Annotated the DEGs to 51 GO terms and 124 KEGG pathways,the expression of DEGs that were enriched in extracellular region function term and proteasome,metabolic pathway were the highest,and the difference were most remarkable.Furthermore,we found ACAA2?ETNPPL?MAP2K6------which are important genes that were associated with Lipid metabolism and the differentiation of skeletal muscle cells------are rewarding of further study.