Heat exposure alters the mRNA expression of growth- and stress-related genes in chicks、
Heat exposure alters the mRNA expression of growth- and stress-related genes in chicks、
复制标题
热暴露会改变雏鸡生长和应激相关基因的 mRNA 表达，
DOI：
10.1016/j.livsci.2017.02.010
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发表时间：
2017
影响因子：
1.8
通讯作者：
Tachibana T
中科院分区：
文献类型：
--
作者：
Okuyama H ;Khan MSI;Tsukada A;Tachibana T
环境温度过高是影响鸡生长的主要应激源。本研究探讨了热暴露对早期蛋鸡生长激素（GH）、胰岛素样生长因子1（IGF 1）、生长激素释放激素（GHRH）、促甲状腺激素释放激素（TRH）和生长抑素（SST）等生长相关基因mRNA表达的影响。此外，我们研究了促肾上腺皮质激素释放激素（CRH）系统的反应，应激调节途径之一，热暴露及其在改变生长相关基因的作用。热暴露4d显著降低了雏鸡的增重、采食量和采食效率，显著升高了直肠温度（P<0.05）。垂体GH、肝脏IGF 1和间脑GHRH mRNA表达水平随热暴露的增加而降低（P<0.05），而TRH和SST的表达水平无明显变化。热暴露降低间脑CRH mRNA表达水平，升高垂体CRH受体2 mRNA和血浆皮质酮（CORT）浓度（P<0.05），提示热暴露影响下丘脑-垂体-肾上腺（HPA）轴。皮下注射CORT 4d后，与热暴露组相似，体重、垂体GH和肝脏IGF 1 mRNA表达均显著降低（P<0.05）。本研究表明，热暴露降低垂体GH和肝脏IGF 1 mRNA的表达，并提出这种变化可能是由CORT引起的。
High ambient temperature, a major stressor, impairs the growth of chickens. In this study, we examined the effect of heat exposure on the mRNA expression of various growth related genes, such as growth hormone (GH), insulin-like growth factor-1 (IGF1), GH-releasing hormone (GHRH), thyrotropin-releasing hormone (TRH), and somatostatin (SST) in layer-type chickens (Gallus gallusdomesticus) at an early age. In addition, we examined the reactivity of the corticotrophin-releasing hormone (CRH) system, one of the stress-regulating pathways, to heat exposure and its role in altering the growth related genes. Four-day heat exposure reduced the body weight gain, feed intake, and feeding efficiency and increased the rectal temperature of chicks (P<0.05). The mRNA expression levels of pituitary GH, liver IGF1, and diencephalic GHRH decreased with heat exposure (P<0.05) whereas the levels of TRH or SST did not change. Heat exposure also reduced the diencephalic mRNA expression level of CRH and increased pituitary CRH receptor-2 mRNA and the plasma corticosterone (CORT) concentration (P<0.05), suggesting that heat exposure affected the hypothamic-pituitary adrenal gland (HPA) axis. Similar to the heat-exposure study, subcutaneous injection of CORT for 4 days decreased body weight, and the mRNA expression of pituitary GH and liver IGF1 (P<0.05). The present study demonstrated that heat exposure reduced the mRNA expressions of pituitary GH and liver IGF1, and suggested that the change in mRNA expression may have been partly caused by CORT.