Background
Intramuscular fat (IMF) is closely related to the tenderness, marbling, juiciness, and flavor of meat. We used a combined transcriptome and metabolome analysis to investigate the molecular mechanisms underlying phenotypic variation among Qinchuan cattle.
Results
The IMF content was relatively high in the meat of Qinchuan cattle bulls and differed among muscle locations, namely the high rib (15.86%), ribeye (14%), striploin (10.44%), and tenderloin (8.67%). CCDC80 and the HOX gene cluster may regulate intramuscular adipose tissue deposition. Moreover, erucic acid (EA) was found to be the main metabolite in Qinchuan beef cattle, with a high concentration in IMF. The deposition of IMF could be regulated by the metabolic pathway for unsaturated fatty acids involving EA and the ACOX3, HACD2, and SCD5 genes. In addition, differentially expressed genes and metabolites were enriched in three major KEGG pathways: purine metabolism, pyrimidine metabolism, and the metabolism of glycine, serine, and threonine.
Conclusions
We identified a significant metabolite, EA, with variation in IMF. Its closely related genes, ACOX3, HACD2, and SCD5, co-regulate the metabolism of unsaturated fatty acids, ultimately affecting the accumulation of intramuscular adipose tissue in Qinchuan cattle. Consequently, Qinchuan cattle are an elite cultivar for high-quality beef production and have great potential for breeding.
A crucial goal of reducing backfat thickness (BFT) is to indirectly improve feed conversion efficiency. This phenotype has been reported in certain papers; however, the molecular mechanism has yet to be fully revealed. Two extreme BFT groups, consisting of four Qinchuan cattle, were chosen for this study. We performed metabolite and transcriptome analyses of blood from cattle with a high BFT (H-BFT with average = 1.19) and from those with a low BFT (L-BFT with average = 0.39). In total, 1106 differentially expressed genes (DEGs) and 86 differentially expressed metabolites (DEMs) were identified in the extreme trait. In addition, serum ceramide was strongly correlated with BFT and could be used as a potential biomarker. Moreover, the most notable finding was that the functional genes (SMPD3 and CERS1) and metabolite (sphingosine 1-phosphate (S1P)) were filtered out and significantly enriched in the processes related to the sphingolipid metabolism. This investigation contributed to a better understanding of the subcutaneous fat depots in cattle. In general, our results indicated that the sphingolipid metabolism, involving major metabolites (serum ceramide and S1P) and key genes (SMPD3 and CERS1), could regulate BFT through blood circulation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.