Department of Basic Medical Veterinary Sciences, Faculty of Veterinary Medicine, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110, Jordan.
Poult Sci. 2019 Feb 1;98(2):991-1001. doi: 10.3382/ps/pey379.
Effects of embryonic thermal manipulation (TM) on mRNA expressional levels and total antioxidant capacity of genes associated with heat-induced oxidative stress (NOX4, GpX2, SOD2, catalase, and AvUCP) in 2 breeds of broiler chicken were investigated. Fertile Cobb and Hubbard eggs (n = 1,200) were divided into 4 treatment groups: Cobb control, Cobb TM, Hubbard control, and Hubbard TM. Control groups were maintained under standard conditions (37.8°C; 56% relative humidity), whereas TM groups were incubated at 39°C and 65% relative humidity for 18 h a day from embryonic days (ED) 10 to 18. On post-hatch day 28, the broilers were subject to acute heat stress (AHS) at 40°C for 7 h. At certain intervals (0, 1, 3, 5, and 7 h), 12 chickens from each of the 4 groups were humanely euthanized, and liver samples were immediately isolated. During AHS, in both breeds, the mRNA expression levels of NOX4, GPx2, SOD2, and catalase in TM chickens were significantly lower than in controls, but AvUCP mRNA expression in the TM group was higher. The total antioxidant capacity and activity of superoxidase dismutase and catalase were significantly lower in the TM than in the control group in both breeds. The results of this study suggest that TM has a long-lasting effect on the acquisition of thermotolerance in 2 broiler chicken breeds as indicated by the reduction of system genes associated with heat-induced oxidative stress.
研究了胚胎热处理（TM）对 2 个肉鸡品种与热诱导氧化应激相关的基因（NOX4、GpX2、SOD2、过氧化氢酶和 AvUCP）的 mRNA 表达水平和总抗氧化能力的影响。将可育的科布和哈伯德鸡蛋（n = 1200）分为 4 个处理组：科布对照组、科布 TM 组、哈伯德对照组和哈伯德 TM 组。对照组在标准条件下（37.8°C；56%相对湿度）饲养，而 TM 组在胚胎第 10 天至第 18 天每天孵化 18 小时，温度为 39°C 和 65%相对湿度。孵化后第 28 天，肉鸡在 40°C 下经历急性热应激（AHS）7 小时。在特定时间间隔（0、1、3、5 和 7 小时），从每组的 12 只鸡中安乐死并立即分离肝脏样本。在 AHS 期间，在两个品种中，TM 鸡的 NOX4、GPx2、SOD2 和过氧化氢酶的 mRNA 表达水平均明显低于对照组，但 TM 组的 AvUCP mRNA 表达水平较高。在两个品种中，TM 组的总抗氧化能力和超氧化物歧化酶和过氧化氢酶的活性均明显低于对照组。本研究结果表明，TM 对 2 个肉鸡品种的耐热性获得具有持久影响，这表现为与热诱导氧化应激相关的系统基因减少。
