Abstract：
Low dissolved oxygen (LO) conditions represent a major environmental challenge to marine life, especially benthic animals. For these organisms, drastic declines in oxygen availability (hypoxic events) can trigger mass mortality events and thus, act as agents of selection influencing the evolution of adaptations. In sea cucumbers, one of the most successful groups of benthic invertebrates, the exposure to hypoxic conditions triggers adaptive adjustments in metabolic rates and behaviour. It is unclear, however, how these adaptive responses are regulated and the genetic mechanisms underpinning them. Here, we addressed this knowledge gap by assessing the genetic regulation (transcription and translation) of hypoxia exposure in the sea cucumber Apostichopus japonicus. Transcriptional and translational gene expression profiles under short- and long-term exposure to low oxygen conditions are tightly associated with extracellular matrix (ECM)-receptor interaction in which laminin and collagen likely have important functions. Finding revealed that genes with a high translational efficiency (TE) had a relatively short upstream open reading frame (uORF) and a high uORF normalized minimal free energy, suggesting that sea cucumbers may respond to hypoxic stress via altered TE. These results provide valuable insights into the regulatory mechanisms that confer adaptive capacity to holothurians to survive oxygen deficiency conditions and may also be used to inform the development of strategies for mitigating the harmful effects of hypoxia on other marine invertebrates facing similar challenges.
摘要：
低溶解氧（LO）条件是海洋生物面临的主要环境挑战，尤其是底栖动物.对于这些生物来说，氧气利用率的急剧下降(缺氧事件)可以引发大规模死亡事件，因此，充当影响适应进化的选择媒介。在海参中，最成功的底栖无脊椎动物群体之一，暴露于低氧条件会触发代谢率和行为的适应性调整。不清楚,然而,这些适应性反应是如何被调节的，以及支撑它们的遗传机制。这里,我们通过评估海参刺参缺氧暴露的遗传调控（转录和翻译）来解决这一知识空白。在短期和长期暴露于低氧条件下的转录和翻译基因表达谱与细胞外基质（ECM）-受体相互作用密切相关，其中层粘连蛋白和胶原蛋白可能具有重要功能。发现具有高翻译效率（TE）的基因具有相对较短的上游开放阅读框（uORF）和较高的uORF归一化最小自由能，这表明海参可能通过改变TE来应对低氧胁迫。这些结果为调节机制提供了有价值的见解，这些机制赋予了海员在缺氧条件下生存的适应能力，也可以用于制定减轻缺氧对面临类似挑战的其他海洋无脊椎动物的有害影响的策略。
