Table 1_Thermal challenge significantly alters gene expression in breast muscle of commercial turkey poults.xlsx

Temperature extremes can compromise livestock welfare and pose serious threats to both economic stability and global food security. In commercial poultry production, newly hatched birds are particularly vulnerable to thermal stress, with growth-selected species such as turkeys being at heightened risk. To cope with temperature challenges, poultry undergo metabolic, physiological, and behavioral adaptations—responses that may have lasting effects on muscle development and, ultimately, meat quality. This study examined transcriptional changes in the breast muscle of young commercial turkey poults exposed to acute thermal stress. Hatchlings were brooded for 3 days at one of three temperatures: control (35 °C), cold (31 °C), or heat (39 °C). Pectoralis major muscle samples were collected, RNA extracted, and transcriptomes were analyzed via deep sequencing. Both cold and heat exposure resulted in reduced body weight compared to control poults. Both thermal stress conditions produced significant differential gene expression. In commercial birds, affected genes were involved in muscle differentiation and development, stress adaptation and apoptosis/protein turnover, energy metabolism and nutrient processing, as well as mitochondrial function and oxidative stress response. Notably, cold stress altered genes related to lipid and glucose metabolism (PDK4, ANGPTL4 and DGAT2), while heat stress affected genes (C/EBPβ and MUSTN1) were associated with differentiation and development and intracellular lipid accumulation. These findings provide a foundation for further studies into the genetic mechanisms driving physiological responses to thermal challenge in poultry.

极端温度会损害畜禽福利，并对经济稳定与全球粮食安全构成严重威胁。在商品家禽养殖中，刚孵出的雏禽对热应激尤为敏感，其中火鸡这类经生长性能选育的品种面临的风险更高。为应对温度胁迫，家禽会产生代谢、生理及行为层面的适应性反应，此类反应可能对肌肉发育乃至最终的肉品质产生持久影响。本研究针对暴露于急性热应激的商品代火鸡雏禽的胸肌转录组变化展开分析。将刚孵出的雏火鸡分别置于三种温度环境下育雏3天：对照组（35℃）、低温应激组（31℃）与高温应激组（39℃）。采集胸大肌样本并提取RNA，随后通过深度测序对转录组进行分析。与对照组雏禽相比，低温与高温暴露组的雏禽体重均出现下降。两种热应激条件均引发了显著的差异基因表达。在商品代家禽中，差异表达基因涉及肌肉分化与发育、应激适应与细胞凋亡/蛋白质周转、能量代谢与营养处理，以及线粒体功能与氧化应激应答等多个生物学过程。值得注意的是，低温应激会调控与脂代谢及糖代谢相关的基因（PDK4、ANGPTL4及DGAT2），而高温应激所影响的基因（C/EBPβ与MUSTN1）则与细胞分化发育及细胞内脂质积累密切相关。本研究结果为后续探究家禽应对温度胁迫的生理应答背后的遗传机制提供了重要基础。