Transcriptome Analysis Of Muscle Tissue Of Jingyuan Chicken And Screening And Identification Of Inosinic Acid Related Genes

In this study,based on the determination of inosinic acid(inosincacid,inosinemonphosphate,IMP),inosine and some physical indexes(shear force,hydraulic capacity,cooking loss rate),transcriptome sequencing(RNA-seq)was used to screen the key differential genes related to IMP.Bio informatics methods were used to analyze the structure and function of differential genes,and molecular biological methods w ere used to construct their eukaryotic expression vectors.A total of 15 males and 15 females of 180-day-old Jingyuan chickens were selected under the same feeding and management conditions.The leg muscle and chest muscle were collected and the shear force,hydraulic capacity,cooking loss rate,IMP and inosine were measured.Transcriptome analysis was carried out on the chest muscle and leg muscle of Jingyuan chicken,and the differential genes related to IMP were screened for structure and function prediction analysis.The main results are as follows:The loss rates of IMP,inosine and cooking in chest muscle of Jingyuan rooster were significantly higher than those in leg muscle(P<0.05or P<0.01 respectively).);IMP,inosine and hydrostatic chicken breast muscle were significantly higher than those in leg muscle(P<0.01),and the cooking loss rate of leg muscle was significantly higher than that of chest muscle(P<0.01).The breast muscle of hen was significantly higher than that of rooster,and the cooking loss rate of leg muscle of hen was significantly higher than that of rooster.There was a significant negative correlation between IMP and inosine in breast muscle and leg muscle of rooster.The IMP of breast muscle and leg muscle of hen was negatively correlated with inosine,cooking loss and hydraulic capacity,and the IMP of leg muscle was negatively correlated with shear force.(2)in transcriptional group,the total number of differentially expressed genes between breast muscle and leg muscle was 2 098,of which 1 146 genes were significantly up-regulated and 952 down-regulated.Differential genes participate in 3117 Gene Ontology term,of which 881 GO term participate in molecular function(Molecular Function,MF),1836 GO term participate in biological process(Biological Process,BP),and 400 GO term participate in cellular component(Cellular Component,CC).At the same time,all the differential genes participated in 75 KEGG pathways.According to the indexes for evaluating meat quality,9 pathways related to meat quality were selected,and 34 differential genes that might be related to meat quality were screened.Furthermore,three differential genes related to AK1,PKM2 and PGM1 were screened out in the purine metabolic pathway related to IMP synthesis.(3)the relative quantitative test showed that the mRNA expression of AK1 gene in chest muscle of Jingyuan chicken was significantly higher than that in leg muscle,and the correlation analysis showed that there was a negative correlation between IMP and mRNA expression of AK1 gene in chest muscle of Jingyuan chicken,the correlation coefficient was-0.404,and there was a positive correlation with mRNA expression of AK1 gene in leg muscle,the correlation coefficient was 0.271.There was a significant positive correlation between IMP and AK1 gene mRNA expression in breast muscle and leg muscle of hens,and the correlation coefficients were 0.534 and 0.538,respectively.(4)Bio informatics analysis of CDS region of AK1 gene in Jingyuan chicken showed that AK1 gene was coexpressed with AMPD1,PKM2 and ADSL.AK1 protein contains 194 amino acids and is a non-transmembrane protein with strong hydrophilic region.AK1 protein may have threonine(Thr),serine(Ser)and tyrosine(Tyr)phosphorylation sites,8,7 and 3 respectively,and may contain 10 B cell epitopes and two CpG islands,which is predicted to play a role in the cytoplasm.α-helix and irregular crimp are the main secondary and tertiary structures of AK1 protein in Jingyuan chicken.(5)the eukaryotic expression vector AK1-pEGFP-N1 of AK1 gene was successfully constructed.The above results provide a theoretical basis for improving the muscle flavor of Jingyuan chicken and the development and utilization of local breed resources,and provide an important basis for the screening of IMP-related genes.At the same time,it has a theoretical support for the further study of the function of AK1 gene.