Exploration And Analysis Of Metabolic Model Of Adipose Tissue In Tibetan Pigs Large Yorkshire Pigs

Fat deposition is one of the economic traits that have attracted much attention in the process of pig production and breeding.The amount and form of pork fat deposition directly affect pork quality and production efficiency,which is the main factor considered by consumers and directly related to the economic development of the pig industry.In this experiment,Tibetan pigs(TP)endemic to China and Large Yorkshire pigs(LW),a large pig breed imported from abroad,were raised to 30 days old,90 days old and 180 days old respectively.The back fat tissue was collected as the research material,and the key genes involved in fat deposition in pig back fat tissue were screened by transcriptome sequencing(RNA-seq).The molecular mechanism of fat deposition in the back fat tissue of plateau Tibetan pigs and Large Yorkshire pigs was studied for the first time.At the same time,RT-q PCR technology was used to quantitatively analyze the selected key candidate genes at the m RNA level,to verify the accuracy of RNA-seq sequencing data,and to further study the regulatory mechanism of these genes in porcine adipose tissue.Transcriptome sequencing technique was used to detect the gene expression in the dorsal adipose tissue of 30-day-old,90-day-old and180-day-old TP.A total of 25 201 genes were detected,of which 20 123 genes were expressed in 3 growth stages.Taking the conditions of Padj<0.05 and |log2Fold Change|>0 as the screening criteria of differentially expressed gene(DEGs),160 DEGs were co-expressed in three growth stages.Finally,GO entries and KEGG Pathway pathway enrichment were carried out on the screened DEGs.Combined with pathway annotation and previous studies,eight important DEGs,such as ACAD11,IGF1,ADAM22,AGPAT2,TP53INP2,FGF18,CLMP and B4GALT5 were selected to be related to lipid synthesis and metabolic function,respectively.Transcriptome sequencing technique was used to detect the gene expression in the dorsal adipose tissue of 30-day-old,90-day-old and180-day-old LW.A total of 25 317 genes were detected,of which 20 515 genes were expressed in three growth stages.According to the same screening criteria as TP,53 DEGs were co-expressed in three growth stages.Finally,53 DEGs selected were enriched by GO entries and KEGG Pathway pathway.Combined with pathway annotation and previous studies,five important DEGs,such as DHCR7,HIF3 A,GFPT2,PCK1 and IGF2BP2 were selected to be related to lipid synthesis and metabolic function,respectively.Based on the combined analysis of TP and LW transcriptome sequencing data,a total of 32 747 positive genes were detected in the dorsal fat tissue of the two varieties,of which 28 565 were expressed.324 DEGs were screened according to the condition of Padj<0.05 and|log2Fold Change|>0.Furthermore,the functions of GO and KEGG Pathway of DEGs were annotated,and 21 DEGs related to fat metabolism and fatty acid synthesis were identified.Through the statistical analysis of the FPKM values of 21 genes and the comprehensive study of their related functions,3 key candidate genes(IDI1,PLAC8,LAP3)were screened on the condition that FPKM values gradually increased at 30 days,90 days and 180 days of TP,and 5 key candidate genes(ACACA,SLC2A4,THRSP,ELOVL5,CHPT1)were screened on the condition that FPKM values increased gradually at 30 days,90 days and 180 days of LW.The selected key candidate genes were verified at RT-q PCR level,and the results were consistent with the trend of transcriptome data.The correlation analysis between RT-q PCR results and pig backfat thickness showed that TP backfat thickness was significantly positively correlated with ACACA,SLC2A4 and THRSP genes,LW backfat thickness was significantly positively correlated with IDI1,ACACA,ELOVL5,LAP3,PLAC8,SLC2A4 and THRSP gene expression,and TP and LW backfat thickness was negatively correlated with CHPT1 gene expression.The results of correlation analysis showed that ACACA,SLC2A4 and THRSP genes may play a positive regulatory role in porcine fat deposition traits,while CHPT1 may have a negative regulatory effect.To sum up,transcriptome sequencing analysis was carried out on the back fat tissue of TP and LW 3 at different ages,and several differentially expressed genes related to fat deposition traits were screened,and 8 key candidate genes were identified by m RNA level and correlation analysis with backfat thickness,which laid a foundation for further study on the regulation mechanism of fat deposition and the mechanism of growth and development in pigs.