Zhou Zhi, Wu Yibo, Zhang Chengkai, Li Can, Chen Guangmei, Yu Xiaopeng, Shi Xiaowei, Xu Yanlai, Wang Lingui, Huang Bo
Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China.
Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China.
Fish Shellfish Immunol. 2017 Aug;67:322-330. doi: 10.1016/j.fsi.2017.06.027. Epub 2017 Jun 9.
Heat stress is the most common factor for coral bleaching, which has increased both in frequency and severity due to global warming. In the present study, the stony coral Acropora aculeus was subjected to acute heat stress and entire transcriptomes were sequenced via the next generation sequencing platform. Four paired-end libraries were constructed and sequenced in two groups, including a control and a heat stress group. A total of 120,319,751 paired-end reads with lengths of 2 × 100 bp were assembled and 55,021 coral-derived genes were obtained. After read mapping and abundance estimation, 9110 differentially expressed genes were obtained in the comparison between the control and heat stress group, including 4465 significantly upregulated and 4645 significantly downregulated genes. Twenty-three GO terms in the Biological Process category were overrepresented for significantly upregulated genes, and divided into six groups according to their relationship. These three groups were related to the NF-κB signal pathway, and the remaining three groups were relevant for pathogen response, immunocyte activation and protein ubiquitination. Forty-three common genes were found in four GO terms, which were directly related to the NF-κB signal pathway. These included 2 NACHT, LRR, PYD domains-containing protein, 5 nucleotide-binding oligomerization domain-containing protein, 29 NLRC3-like protein, 4 NLRC5-like protein, and 3 uncharacterized protein. For significantly downregulated genes, 27 overrepresented GO terms were found in the Biological Process category, which were relevant to protein ubiquitination and ATP metabolism. Our results indicate that heat stress suppressed the immune response level via the NLRC3-like protein, the fine-tuning of protein turnover activity, and ATP metabolism. This might disrupt the balance of coral-zooxanthellae symbiosis and result in the bleaching of the coral A. aculeus.
热应激是珊瑚白化最常见的因素，由于全球变暖，其发生频率和严重程度都有所增加。在本研究中，将石珊瑚尖锐鹿角珊瑚置于急性热应激条件下，并通过下一代测序平台对其整个转录组进行测序。构建了四个双末端文库，并分为两组进行测序，包括一个对照组和一个热应激组。共组装了120319751条长度为2×100 bp的双末端读段，获得了55021个源自珊瑚的基因。经过读段比对和丰度估计，在对照组和热应激组的比较中获得了9110个差异表达基因，其中包括4465个显著上调基因和4645个显著下调基因。生物学过程类别中的23个GO术语在显著上调基因中过度富集，并根据它们的关系分为六组。这三组与NF-κB信号通路相关，其余三组与病原体反应、免疫细胞激活和蛋白质泛素化有关。在四个与NF-κB信号通路直接相关的GO术语中发现了43个共同基因。其中包括2个含NACHT、LRR、PYD结构域的蛋白、5个含核苷酸结合寡聚化结构域的蛋白、29个NLRC3样蛋白、4个NLRC5样蛋白和3个未表征蛋白。对于显著下调的基因，在生物学过程类别中发现了27个过度富集的GO术语，它们与蛋白质泛素化和ATP代谢有关。我们的结果表明，热应激通过NLRC3样蛋白、蛋白质周转活性的微调以及ATP代谢抑制了免疫反应水平。这可能会破坏珊瑚-虫黄藻共生关系的平衡，导致尖锐鹿角珊瑚白化。
