Adaptations to the mudflat: Insights from physiological and transcriptional responses to thermal stress in a burrowing bivalve Sinonovacula constricta
Adaptations to the mudflat: Insights from physiological and transcriptional responses to thermal stress in a burrowing bivalve Sinonovacula constricta
复制标题
对泥滩的适应：穴居双壳类缢蛏对热应激的生理和转录反应的见解
DOI：
10.1016/j.scitotenv.2019.136280
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发表时间：
2020
影响因子：
9.8
通讯作者：
Dong Yun-wei
中科院分区：
文献类型：
--
作者：
Zhang Wen-yi;Storey Kenneth B.;Dong Yun-wei
了解生物体对其栖息地的温度变化的生理适应是预测全球气候变化对种群动态可能产生的影响的第一步。泥滩是潮间带的重要组成部分，经历着极端和波动的温度。在这种情况下，物种可能会受到全球变暖的影响。本研究通过分析潮间带泥滩潜在的工作温度，以及评价一种典型的穴居双壳类动物的心脏性能和对热应激的转录反应，来探索穴居物种对潮间带泥滩生活的生理适应。文蛤在有上覆空气的泥中表现出比在上覆水中更高的热亚致死极限，这表明在浮现过程中对迅速变化的环境温度和热环境有适应。这一亚致死极限远高于实际栖息地的最高工作温度，表明可能存在一个缓冲区，以确保在全球变暖可能发生的意外高温下生存。作为对高温的响应，收缩链球菌通过上调Bcl2相关基因3(BAG3)和热休克蛋白的表达来应对高温对蛋白质动态平衡的不利影响，从而表现出常见的热应激反应。关键基因的表达增加，包括钼辅助因子合成3(MOCS3)、寡核苷酸酶(REX2)和核因子κappaB抑制因子α(NfiA)，可能进一步缓解退化期热应激的影响，推迟文蛤达到热亚致死极限的情况，从而帮助抵抗退潮期间的高温。这些结果清楚地说明了穴居双壳类在生理和分子水平上对潮间带泥滩生活的显著适应，并可以为有助于泥滩物种在不断变化的全球气候中生存的潜在生理或进化反应提供洞察。
Understanding physiological adaptations of organisms to temperature changes that characterize their habitat is the first step in predicting the putative effects of global climate change on population dynamics. Mudflats are an important part of the intertidal zone and experience extreme and fluctuating temperatures. Therein, species would be potentially susceptible to global warming. The present study explored physiological adaptations of burrowing species to life in an intertidal mudflat by analyzing the potential operative temperatures in the mudflat, and assessing cardiac performance and the transcriptional response to thermal stress by a typical burrowing bivalve, the razor clamSinonovacula constrictain different thermal environments, mimicking conditions during low tides. Clams showed higher thermal sublethal limits in mud with overlying air than in mud with overlying water, indicating an adaptation to rapidly changing ambient temperatures and thermal environments during emersion. This sublethal limit was far above the maximum operative temperature in the actual habitat site and suggests a potential buffer zone to ensure survival under unexpected high temperatures, that could occur with global warming. In response to high temperature,S.constrictaexhibited the common heat stress response by up-regulating expression of the Bcl2-associated athanogene 3 (BAG3) and heat shock proteins to cope with the adverse effects of high temperature on protein homeostasis. Increased expression of key genes, including molybdenum cofactor synthesis 3 (MOCS3), oligoribonuclease (REX2), and NFκappaB inhibitor alpha (NFIA) may further remit the effect of thermal stress during the emersion period and delay a situation where clams reach their thermal sublethal limit, thereby helping to endure high temperature during low tide. These results clearly illustrate significant adaptations of a burrowing bivalve to life in intertidal mudflats at both physiological and molecular levels and can provide insights into potential physiological or evolutionary responses that could aid survival of mudflat species in a changing global climate.