College of Animal Science and Technology, Northwest A&F University, Yangling712100, Shaanxi, China.
National Beef Cattle Improvement Centre, College of Animal Science and Technology, Northwest A&F University, Yangling712100, Shaanxi, China.
J Agric Food Chem. 2022 Nov 23;70(46):14641-14653. doi: 10.1021/acs.jafc.2c05719. Epub 2022 Nov 14.
Fat deposition significantly impacts the meat yield and the meat quality of beef cattle, which is closely associated with the preadipocyte proliferation and differentiation. Bta-miR-493 is expressed differentially in the backfat of Qinchuan cattle of various ages, and it may be involved in the fat accumulation of beef cattle. However, the role and functional mechanism of bta-miR-493 in fat deposition are still unclear. Tissue-specific expression analysis showed that the level of bta-miR-493 was moderately abundant in the adipose tissues of beef cattle. Moreover, the expression of bta-miR-493 in perirenal fat, subcutaneous fat, and longissimus dorsi muscle of Japanese black cattle was significantly higher than that in Qinchuan cattle. EdU staining, cell counting assay, and Oil Red O staining indicated that bta-miR-493 promoted the proliferation of bovine preadipocytes but inhibited their differentiation. The dual luciferase assay and transcriptomic analysis confirmed that bone morphogenetic protein receptor 1A () is a target gene of bta-miR-493. Moreover, rescue experiments showed that bta-miR-493 could promote bovine preadipocyte proliferation but inhibit their differentiation by targeting via the TGFβ/BMP and p38MAPK signaling pathways. Overall, our findings revealed a bta-miR-493--TGFβ/BMP/p38MAPK regulatory axis that will serve as a theoretical foundation for the molecular breeding of beef cattle with high intramuscular fat deposition.
脂肪沉积显著影响肉牛的产肉量和肉质，这与前体脂肪细胞的增殖和分化密切相关。Bta-miR-493 在不同年龄秦川牛的背脂中表达差异，可能参与了肉牛的脂肪积累。然而，bta-miR-493 在脂肪沉积中的作用和功能机制尚不清楚。组织特异性表达分析表明，bta-miR-493 在肉牛的脂肪组织中表达水平中等丰富。此外，日本黑牛的肾周脂肪、皮下脂肪和背最长肌中 bta-miR-493 的表达明显高于秦川牛。EdU 染色、细胞计数测定和油红 O 染色表明，bta-miR-493 促进牛前体脂肪细胞的增殖，但抑制其分化。双荧光素酶报告基因检测和转录组分析证实骨形态发生蛋白受体 1A () 是 bta-miR-493 的靶基因。此外，挽救实验表明，bta-miR-493 通过靶向 通过 TGFβ/BMP 和 p38MAPK 信号通路促进牛前体脂肪细胞的增殖但抑制其分化。总之，我们的研究结果揭示了一个 bta-miR-493--TGFβ/BMP/p38MAPK 调控轴，可为高肌内脂肪沉积肉牛的分子育种提供理论基础。
