Adipogenesis, fibrogenesis and myogenesis related gene expression in longissimus muscle of high and low marbling beef cattle

Abstract

Intramuscular fat (IMF) content is critical for the eating quality of beef, but mechanisms regulating IMF deposition remain unsystematically defined. Myogenic and adipogenic cells come from a similar pool of progenitor cells. We hypothesized that adipogenic differentiation was primed in high marbling cattle. To test, two groups of cattle with high and low marbling levels were selected from a uniform group of cattle with the same genetic background and management. By RNA-sequencing, differentially expressed genes were identified. Myogenic genes (eg. MyoG) were up-regulated in the low marbling group, while apolipoprotein E genes (eg. APOE) were down-regulated. Meanwhile, the expression of fibrogenic genes was mixed, with collagen isoforms, COL11A2 and COL22A1 more highly expressed in the high marbling group, and COL14A1, COL16A1, COL1A1 and COL1A2 more lowly expressed. In summary, our data show that adipogenesis was elevated in high marbling cattle accompanied by weakened myogenesis, pointing to the developmental origins of differences in beef marbling.