Chronic heat stress (CHS) is a detrimental environmental stressor with a negative impact on the meat quality of broilers. However, the underlying mechanisms are not fully understood. This study investigates the effects of CHS on long non-coding RNA (lncRNA) expression and muscle injury in broilers, with a focus on its implications for meat quality. The results showed that CHS diminished breast muscle yield, elevated abdominal fat deposition, induced cellular apoptosis (P < 0.05), and caused myofibrosis. Transcriptomic analysis revealed 151 differentially expressed (DE) lncRNAs when comparing the normal control (NC) and HS groups, 214 DE lncRNAs when comparing the HS and PF groups, and 79 DE lncRNAs when comparing the NC and pair-fed (PF) groups. After eliminating the confounding effect of feed intake, 68 lncRNAs were identified, primarily associated with cellular growth and death, signal transduction, and metabolic regulation. Notably, the apoptosis-related pathway P53, lysosomes, and the fibrosis-related gene TGF-β2 were significantly upregulated by lncRNAs. These findings indicate that chronic heat stress induces cellular apoptosis and muscle injury through lncRNA, leading to connective tissue accumulation, which likely contributes to reduced breast muscle yield and meat quality in broilers.

中文翻译：

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揭示长链非编码 RNA 在慢性热应激诱导的肉鸡肌肉损伤中的作用


慢性热应激 （CHS） 是一种有害的环境应激源，对肉鸡的肉质有负面影响。然而，其潜在机制尚不完全清楚。本研究调查了 CHS 对肉鸡长链非编码 RNA （lncRNA） 表达和肌肉损伤的影响，重点是其对肉质的影响。结果显示，CHS 降低乳房肌肉产量，增加腹部脂肪沉积，诱导细胞凋亡 （P < 0.05），并引起肌纤维化。转录组学分析显示，当比较正常对照 （NC） 组和 HS 组时，有 151 个差异表达 （DE） lncRNA，当比较 HS 和 PF 组时，有 214 个 DE lncRNA，当比较 NC 和配对喂养 （PF） 组时，有 79 个 DE lncRNA。在消除采食量的混杂效应后，鉴定出 68 个 lncRNA，主要与细胞生长和死亡、信号转导和代谢调节有关。值得注意的是，细胞凋亡相关通路 P53 、溶酶体和纤维化相关基因 TGF-β2 被 lncRNAs 显著上调。这些发现表明，慢性热应激通过 lncRNA 诱导细胞凋亡和肌肉损伤，导致结缔组织积累，这可能导致肉鸡的乳房肌肉产量和肉质降低。