Lassiter Kentu, Kong Byungwhi Caleb, Piekarski-Welsher Alissa, Dridi Sami, Bottje Walter Gay
Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States.
Adisseo USA, Alpharetta, GA, United States.
Front Physiol. 2019 Feb 26;10:126. doi: 10.3389/fphys.2019.00126. eCollection 2019.
Feed efficiency (FE, gain to feed) is an important genetic trait as 70% of the cost of raising animals is due to feed costs. The objective of this study was to determine mRNA expression of genes involved in muscle development and hypertrophy, and the insulin receptor-signaling pathway in breast muscle associated with the phenotypic expression of FE. Breast muscle samples were obtained from Pedigree Male (PedM) broilers (8 to 10 week old) that had been individually phenotyped for FE between 6 and 7 week of age. The high FE group gained more weight but consumed the same amount of feed compared to the low FE group. Total RNA was extracted from breast muscle ( = 6 per group) and mRNA expression of target genes was determined by real-time quantitative PCR. Targeted gene expression analysis in breast muscle of the high FE phenotype revealed that muscle development may be fostered in the high FE PedM phenotype by down-regulation several components of the myostatin signaling pathway genes combined with upregulation of genes that enhance muscle formation and growth. There was also evidence of genetic architecture that would foster muscle protein synthesis in the high FE phenotype. A clear indication of differences in insulin signaling between high and low FE phenotypes was not apparent in this study. These findings indicate that a gene expression architecture is present in breast muscle of PedM broilers exhibiting high FE that would support enhanced muscle development-differentiation as well as protein synthesis compared to PedM broilers exhibiting low FE.
饲料效率（FE，增重与采食量之比）是一项重要的遗传性状，因为养殖动物成本的70%归因于饲料成本。本研究的目的是确定参与肌肉发育和肥大以及胰岛素受体信号通路的基因在胸肌中的mRNA表达，这些基因与饲料效率的表型表达相关。胸肌样本取自系谱雄性（PedM）肉鸡（8至10周龄），这些肉鸡在6至7周龄时已对饲料效率进行了个体表型测定。与低饲料效率组相比，高饲料效率组体重增加更多，但采食量相同。从胸肌中提取总RNA（每组n = 6），并通过实时定量PCR测定靶基因的mRNA表达。对高饲料效率表型的胸肌进行靶向基因表达分析发现，高饲料效率的PedM表型可能通过下调肌肉生长抑制素信号通路基因的几个组分，同时上调增强肌肉形成和生长的基因来促进肌肉发育。也有证据表明存在一种遗传结构，可促进高饲料效率表型中的肌肉蛋白合成。在本研究中，高、低饲料效率表型之间胰岛素信号差异的明显迹象并不明显。这些发现表明，与低饲料效率的PedM肉鸡相比，高饲料效率的PedM肉鸡胸肌中存在一种基因表达结构，该结构支持增强的肌肉发育分化以及蛋白质合成。
