Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, Taiwan.
Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, Taiwan; Institute of Oceanography, National Taiwan University, Taiwan.
Sci Total Environ. 2022 Oct 20;844:156962. doi: 10.1016/j.scitotenv.2022.156962. Epub 2022 Jun 30.
Climate changes, such as extreme temperature shifts, can have a direct and significant impact on animals living in the ocean system. Ectothermic animals may undergo concerted metabolic shifts in response to ambient temperature changes. The physiological and molecular adaptations in cephalopods during their early life stages are largely unknown due to the challenge of rearing them outside of a natural marine environment. To overcome this obstacle, we established a pelagic bigfin reef squid (Sepioteuthis lessoniana) culture facility, which allowed us to monitor the effects of ambient thermal elevation and fluctuation on cephalopod embryos/larvae. By carefully observing embryonic development in the breeding facility, we defined 23 stages of bigfin reef squid embryonic development, beginning at stage 12 (blastocyst; 72 h post-egg laying) and continuing through hatching (~1 month post-egg laying). Since temperature recordings from the bigfin reef squid natural habitats have shown a steady rise over the past decade, we examined energy substrate utilization and cellular/metabolic responses in developing animals under different temperature conditions. As the ambient temperature increased by 7 °C, hatching larvae favored aerobic metabolism by about 2.3-fold. Short-term environmental warming stress inhibited oxygen consumption but did not affect ammonium excretion in stage (St.) 25 larvae. Meanwhile, an aerobic metabolism-related marker (CoxI) and a cellular stress-responsive marker (HSP70) were rapidly up-regulated upon acute warming treatments. In addition, our simulations of temperature oscillations mimicking natural daily rhythms did not result in significant changes in metabolic processes in St. 25 animals. As the ambient temperature increased by 7 °C, referred to as heatwave conditions, CoxI, HSP70, and antioxidant molecule (SOD) were stimulated, indicating the importance of cellular and metabolic adjustments. As with other aquatic species with high metabolic rates, squid larvae in the tropical/sub-tropical climate zone undergo adaptive metabolic shifts to maintain physiological functions and prevent excessive oxidative stress under environmental warming.
气候变化，如极端温度变化，可能对生活在海洋系统中的动物产生直接而重大的影响。变温动物可能会协同代谢转变，以应对环境温度变化。由于在自然海洋环境之外饲养它们具有挑战性，因此头足类动物在其早期生命阶段的生理和分子适应在很大程度上是未知的。为了克服这一障碍，我们建立了一个远洋大鳍鱿鱼（Sepioteuthis lessoniana）养殖设施，使我们能够监测环境热升高和波动对头足类动物胚胎/幼虫的影响。通过在养殖设施中仔细观察胚胎发育，我们定义了大鳍鱿鱼胚胎发育的 23 个阶段，从第 12 阶段（囊胚；产卵后 72 小时）开始，一直持续到孵化（产卵后约 1 个月）。由于大鳍鱿鱼自然栖息地的温度记录显示过去十年来一直在稳步上升，因此我们在不同温度条件下研究了发育中动物的能量底物利用和细胞/代谢反应。当环境温度升高 7°C 时，孵化幼虫通过约 2.3 倍的有氧代谢来优先利用。短期环境变暖应激抑制了耗氧量，但对第 25 阶段幼虫的氨排泄没有影响。同时，有氧代谢相关标志物（CoxI）和细胞应激响应标志物（HSP70）在急性变暖处理后迅速上调。此外，我们模拟自然日节律的温度波动模拟不会导致第 25 阶段动物代谢过程发生显著变化。当环境温度升高 7°C 时，称为热浪条件，CoxI、HSP70 和抗氧化分子（SOD）被刺激，表明细胞和代谢调整的重要性。与其他具有高代谢率的水生物种一样，热带/亚热带气候区的鱿鱼幼虫经历适应性代谢转变，以维持生理功能并防止在环境变暖下过度氧化应激。
