Key Laboratory of Combining Farming and Animal Husbandry of Ministry of Agriculture, Institute of Animal Husbandry, Heilongjiang Academy of Agricultural Sciences, Harbin, China.
Heilongjiang Journal Press of Agricultural Science and Technology, Heilongjiang Academy of Agricultural Sciences, Harbin, China.
PLoS One. 2021 Feb 24;16(2):e0247559. doi: 10.1371/journal.pone.0247559. eCollection 2021.
The intramuscular fat (IMF) content and fatty acid composition are important meat quality traits that are mostly affected by the cattle breed. Muscle, adipose tissue and liver are important organs involved in the development of intramuscular adipose tissue. Thus, we hypothesized that there were marked differences in the adipogenesis and lipid metabolism of these tissues between Wagyu-cross and Holstein steers during the finishing phases. To test this hypothesis, we analyzed the expression levels of adipogenesis- and lipid metabolism-related genes in longissimus muscle (LM), subcutaneous fat (SCF) and liver from Wagyu-cross and Holstein steers at 26 months of age. The IMF content and fatty acid profile of LM were determined. Wagyu-cross steers had a higher IMF content and MUFA percentages in the LM than Holstein steers (P<0.05). The relative expression of FGF2, COL1A1, SREBP1c, SCD1, GRP78 and LEP was greater in the LM of Wagyu-cross steers than in Holstein steers (P<0.05). In contrast, Holstein steer SCF had higher (P<0.05) mRNA expression levels of FABP4 and ADIPOQ than Wagyu-cross steers. In the liver, the expression of SREBP1c and GRP78 in Wagyu-cross steers was significantly higher than that in Holstein steers (P<0.05). The results demonstrate that both intramuscular adipogenesis and fibrogenesis are enhanced in Wagyu-cross steers compared with Holstein steers during the finishing phase and that IMF deposition is positively correlated with the maturity of SCF and hepatic lipid accumulation in Wagyu-cross steers.
肌内脂肪（IMF）含量和脂肪酸组成是重要的肉质性状，主要受牛品种影响。肌肉、脂肪组织和肝脏是参与肌内脂肪发育的重要器官。因此，我们假设在育肥阶段，和牛杂交牛和荷斯坦牛的这些组织的脂肪生成和脂质代谢存在明显差异。为了验证这一假设，我们分析了 26 月龄和牛杂交牛和荷斯坦牛的背最长肌（LM）、皮下脂肪（SCF）和肝脏中与脂肪生成和脂质代谢相关基因的表达水平。并测定了 LM 的 IMF 含量和脂肪酸谱。和牛杂交牛的 LM 的 IMF 含量和 MUFA 百分比高于荷斯坦牛（P<0.05）。和牛杂交牛的 LM 中 FGF2、COL1A1、SREBP1c、SCD1、GRP78 和 LEP 的相对表达量高于荷斯坦牛（P<0.05）。相比之下，荷斯坦牛的 SCF 中 FABP4 和 ADIPOQ 的 mRNA 表达水平较高（P<0.05）。在肝脏中，和牛杂交牛的 SREBP1c 和 GRP78 的表达明显高于荷斯坦牛（P<0.05）。结果表明，与荷斯坦牛相比，和牛杂交牛在育肥阶段的肌内脂肪生成和纤维化增强，并且 IMF 沉积与 SCF 的成熟以及和牛杂交牛肝脏脂质积累呈正相关。
