Granulosa cells (GCs) play an important role in the development of follicles. In this study, we investigate the impact of heat stress at 41°C and 43°C on duck GCs' proliferation and steroids secretion. And, the transcriptomic responses to heat treatment were examined using RNA-sequencing analysis. Digital gene expression profiling was used to screen and identify differentially expressed genes (fold change ≥ 2 and Q value < 0.05). Further, the differential expression genes (DEGs) were classified into GO categories and KEGG pathways. The results show that duck GCs blocked in the G1 phase were increased on exposure to heat stress. Meanwhile, the expression of proliferative genes, which were essential for the transition from G1 to S phase, was inhibited. At the same time, heat stress inhibited the estradiol synthesis of GCs by decreasing CYP11A1 and CYP19A1 gene expression. A total of 241 DEGs including 181 upregulated and 60 downregulated ones were identified. Transcriptome result shows that heat shock protein and CXC chemokines gene were significantly activated during heat stress. While collagenases (MMP1 and MMP13) and strome lysins (MMP3) were downregulated. And, the hedgehog signaling pathway may be a prosurvival adaptive response under heat stress. These results offer a basis for better understanding the molecular mechanism underlying lay-eggs-less in ducks under heat stress.

中文翻译：

---

热应激对鸭颗粒细胞增殖、类固醇合成及基因表达的影响

颗粒细胞 (GCs) 在卵泡的发育中起重要作用。在这项研究中，我们研究了 41°C 和 43°C 的热应激对鸭 GCs 增殖和类固醇分泌的影响。并且，使用 RNA 测序分析检查了对热处理的转录组学反应。数字基因表达谱用于筛选和鉴定差异表达基因（倍数变化≥2和Q值 < 0.05）。此外，差异表达基因 (DEG) 被分为 GO 类别和 KEGG 通路。结果表明，在 G1 期受阻的鸭 GC 在暴露于热应激时增加。同时，抑制了从 G1 期到 S 期过渡所必需的增殖基因的表达。同时，热应激通过降低CYP11A1和CYP19A1基因表达抑制 GCs 的雌二醇合成。共鉴定出 241 个 DEG，包括 181 个上调和 60 个下调。转录组结果显示热休克蛋白和CXC趋化因子基因在热应激过程中显着激活。而胶原酶（MMP1和MMP13）和基质溶素（MMP3 ) 被下调。并且，hedgehog 信号通路可能是热应激下的促生存适应性反应。这些结果为更好地理解热应激下鸭少产蛋的分子机制提供了基础。