组蛋白乙酰化修饰对刺参HSPs转录表达和耐热性的调控机理

The sea cucumber Apostichopus japonicus has been exploited as a very important aquaculture species with the highest value in China. Water temperature is a key environmental factor influencing growth and metabolism of A. japonicus. In recent years, extreme high temperature in summer has led to widespread mortality of A. japonicus in the northern coasts and many aquacultural ponds of China. Therefore, it is necessary to take countermeasures against heat threat in A. japonicus aquaculture. This project will focus on the roles of histone acetylation on HSPs transcription and thermotolerance in A. japonicus, based on our previous research findings. First, we will study the characteristics of histone acetylation on HSPs under heat stress, and verify its roles on HSPs transcription by correlation analysis with HSPs mRNA expression. Second, we will study the combining capacity of genes HSPs with HSF1 and RNAPII, under deacetylation and acetylation status respectively. Additionally, we will carry out HDACs and HATs inhibitor experiment in vivo in order to analyze the effects of different histone acetylation levels on HSPs transcription and thermotolerance in A. japonicus. This research will provide new insights for heat shock response in invertebrates, echinodermata particularly. Meanwhile, this research will provide theoretical basis for heat-resistance breeding, which is meaningful for sustainable development of A. japonicus aquaculture.

刺参是我国海洋农业单种产值最高的养殖对象，水温是影响其生长和代谢最重要的环境因素之一。由于夏季极端温度频发，池塘和浅海围堰中养殖的刺参出现大面积死亡现象，应对高温环境胁迫是刺参养殖生产面临的重要的现实问题。本项目拟在前期工作基础上，研究热胁迫下组蛋白对HSPs的乙酰化修饰特征，与HSPs的mRNA表达量关联分析，明确组蛋白乙酰化对HSPs转录表达的调控作用；研究组蛋白乙酰化对HSF1、RNA聚合酶II与HSPs基因的结合能力的影响，剖析组蛋白乙酰化对HSPs表达的调控机理；开展组蛋白乙酰转移酶和去乙酰化酶抑制剂的体内实验，分析不同组蛋白乙酰化水平对刺参HSPs转录表达和耐热性的影响。以上研究内容将为无脊椎动物特别是棘皮动物热胁迫响应机制的研究提供新认知，同时为刺参耐高温品种的选育和遗传改良提供科学的指导，对促进刺参养殖产业的可持续发展具有重要的意义。

由于夏季极端温度频发，池塘和浅海围堰中养殖的刺参出现大面积死亡现象，应对高温环境胁迫是刺参养殖生产面临的重要的现实问题。本项目系统围绕热胁迫下组蛋白对HSPs的乙酰化修饰特征、HSPs转录表达的调控作用机理、HSPs转录表达与刺参耐热性状关联分析开展研究。首次证实乙酰化作为翻译后修饰参与刺参热胁迫下基因响应，构建了热胁迫下刺参乙酰化差异蛋白互作网络。发现了组蛋白乙酰化对HSPs的修饰位点和修饰特征，并关联分析了刺参HSPs在mRNA水平对热胁迫响应的动力学变化过程。分析了microRNA在热胁迫下表达特点，并获得microRNA-mRNA作用对，共同揭示了刺参热胁迫下基因转录的调控机制。为进一步研究HSPs表达与刺参耐热性状的关系，本项目测定了不同季节自然养殖状态下刺参基因表达情况，揭示了HSPs等基因表达与耐热性状的相关性。系列工作为棘皮动物热胁迫响应机制的研究提供新认知，同时为刺参耐高温品种的选育和遗传改良提供科学的指导。