Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
BMC Genomics. 2020 Jan 21;21(1):68. doi: 10.1186/s12864-020-6480-9.
Global climate change is predicted to force the bathymetric migrations of shallow-water marine invertebrates. Hydrostatic pressure is proposed to be one of the major environmental factors limiting the vertical distribution of extant marine invertebrates. However, the high-pressure acclimation mechanisms are not yet fully understood.
In this study, the shallow-water sea cucumber Apostichopus japonicus was incubated at 15 and 25 MPa at 15 °C for 24 h, and subjected to comparative transcriptome analysis. Nine samples were sequenced and assembled into 553,507 unigenes with a N50 length of 1204 bp. Three groups of differentially expressed genes (DEGs) were identified according to their gene expression patterns, including 38 linearly related DEGs whose expression patterns were linearly correlated with hydrostatic pressure, 244 pressure-sensitive DEGs which were up-regulated at both 15 and 25 MPa, and 257 high-pressure-induced DEGs which were up-regulated at 25 MPa but not up-regulated at 15 MPa.
Our results indicated that the genes and biological processes involving high-pressure acclimation are similar to those related to deep-sea adaptation. In addition to representative biological processes involving deep-sea adaptation (such as antioxidation, immune response, genetic information processing, and DNA repair), two biological processes, namely, ubiquitination and endocytosis, which can collaborate with each other and regulate the elimination of misfolded proteins, also responded to high-pressure exposure in our study. The up-regulation of these two processes suggested that high hydrostatic pressure would lead to the increase of misfolded protein synthesis, and this may result in the death of shallow-water sea cucumber under high-pressure exposure.
全球气候变化预计将迫使浅海海洋无脊椎动物进行水深迁移。静水压力被认为是限制现存海洋无脊椎动物垂直分布的主要环境因素之一。然而，高压适应机制尚未完全了解。
在这项研究中，将浅海海参刺参（Apostichopus japonicus）在 15 和 25 MPa 下于 15°C 孵育 24 小时，并进行比较转录组分析。对九个样本进行测序，并组装成 553,507 个具有 1204 bp N50 长度的非基因。根据其基因表达模式，确定了三组差异表达基因（DEGs），包括 38 个线性相关 DEGs，其表达模式与静水压力呈线性相关，244 个压力敏感 DEGs，在 15 和 25 MPa 下均上调，以及 257 个高压诱导 DEGs，在 25 MPa 上调，但在 15 MPa 下未上调。
我们的结果表明，涉及高压适应的基因和生物学过程与深海适应相关的基因和生物学过程相似。除了涉及深海适应的代表性生物学过程（如抗氧化、免疫反应、遗传信息处理和 DNA 修复）外，两种生物学过程，即泛素化和内吞作用，它们可以相互协作并调节错误折叠蛋白质的消除，在我们的研究中也对高压暴露做出了响应。这两个过程的上调表明，高静水压力会导致错误折叠蛋白质合成增加，这可能导致浅海海参在高压暴露下死亡。
