Traylor-Knowles Nikki, Rose Noah H, Sheets Elizabeth A, Palumbi Stephen R
Biol Bull. 2017 Apr;232(2):91-100. doi: 10.1086/692717. Epub 2017 May 31.
Corals respond to heat pulses that cause bleaching with massive transcriptional change, but the immediate responses to stress that lead up to these shifts have never been detailed. Understanding these early signals could be important for identifying the regulatory mechanisms responsible for bleaching and how these mechanisms vary between more and less resilient corals. Using RNA sequencing (RNAseq) and sampling every 30 minutes during a short-term heat shock, we found that components of the transcriptome were significantly upregulated within 90 min and after a temperature increase of +2 °C. The developmental transcription factor, Krüppel-like factor 7, was highly expressed within 60 min, and stress-related transcription factors such as Elk-3 were highly expressed starting at 240 min. The sets of genes enriched for early transcriptional response to heat stress included heat shock proteins, small GTPases, and proteasome genes. Retrovirus-related Pol polyproteins from transposons were significantly expressed throughout the whole experiment. Lastly, we propose a model for early transcriptional regulation of protein degradation and cell adhesion response that may ultimately lead to the bleaching and stress response.
珊瑚对导致白化的热脉冲会产生大规模的转录变化，但导致这些变化的对压力的即时反应从未被详细研究过。了解这些早期信号对于确定导致白化的调控机制以及这些机制在抗逆性较强和较弱的珊瑚之间如何变化可能很重要。通过在短期热休克期间每30分钟进行一次RNA测序（RNAseq）和采样，我们发现转录组的成分在90分钟内以及温度升高2°C后显著上调。发育转录因子Krüppel样因子7在60分钟内高度表达，而应激相关转录因子如Elk-3在240分钟开始高度表达。富集于对热应激早期转录反应的基因集包括热休克蛋白、小GTP酶和蛋白酶体基因。来自转座子的逆转录病毒相关Pol多蛋白在整个实验过程中都有显著表达。最后，我们提出了一个蛋白质降解和细胞粘附反应的早期转录调控模型，该模型最终可能导致白化和应激反应。
