Abstract：
Marine heatwaves (MHWs) have a significant impact on intertidal bivalves and the ecosystems they sustain, causing the destruction of organisms\' original habitats. Saccostrea mordax mainly inhabits the intertidal zone around the equator, exhibiting potential tolerance to high temperatures and maybe a species suitable for habitat restoration. However, an understanding about the tolerance mechanism of S. mordax to high temperatures is unclear. It is also unknown the extent to which S. mordax can tolerate repeated heatwaves of increasing intensity and frequency. Here, we simulated the effects of two scenarios of MHWs and measured the physiological and biochemical responses and gene expression spectrum of S. mordax. The predicted responses varied greatly across heatwaves, and no heatwave had a significant impact on the survival of S. mordax. Specifically, there were no statistically significant changes apparent in the standard metabolic rate and the activities of enzymes of the oyster during repeated heatwaves. S. mordax exposed to high-intensity heatwaves enhanced their standard metabolic rate to fuel essential physiological maintenance and increasing activity of SOD and expression of HSP70/90. These strategies are presumably at the expense of functions related to immunity and growth, as best exemplified by significant depressions in activities of enzymes (NaK, CaMg, T-ATP, and AKP) and expression levels of genes (Rab, eEF-2, HMGR, Rac1, SGK, Rab8, etc.). The performance status of S. mordax tends to improve by implementing a suite of less energy-costly compensatory mechanisms at various levels of biological organization when re-exposed to heatwaves. The adaptive abilities shown by S. mordax indicate that they can play a crucial role in the restoration of oyster reefs in tropical seas.
摘要：
海洋热浪（MHW）对潮间带双壳类动物及其维持的生态系统产生重大影响，造成生物原始栖息地的破坏。Saccostreamordax主要居住在赤道周围的潮间带，表现出对高温的潜在耐受性，可能是适合栖息地恢复的物种。然而,关于S.mordax对高温的耐受机制的理解尚不清楚。还不清楚S.mordax可以容忍强度和频率不断增加的重复热浪的程度。这里,我们模拟了MHW的两种情况的影响，并测量了S.mordax的生理生化反应和基因表达谱。预测的响应在热浪中变化很大，并且没有热浪对S.mordax的生存产生重大影响。具体来说,在反复的热浪中，牡蛎的标准代谢率和酶活性没有统计学上的显着变化。暴露于高强度热浪的S.mordax可提高其标准代谢率，以促进基本的生理维持，并增加SOD的活性和HSP70/90的表达。这些策略大概是以牺牲与免疫和生长有关的功能为代价的，最好的例子是酶活性的显著降低(NaK，CaMg,T-ATP,和AKP）和基因的表达水平（Rab，eEF-2,HMGR,Rac1,SGK,Rab8等).S.mordax的性能状态倾向于通过在重新暴露于热浪时在生物组织的各个层面上实施一套能耗较低的补偿机制来改善。S.mordax显示的适应能力表明，它们可以在热带海洋牡蛎礁的恢复中发挥关键作用。
