To live or die: "Fine-tuning" adaptation revealed by systemic analyses in symbiotic bathymodiolin mussels from diverse deep-sea extreme ecosystems
To live or die: "Fine-tuning" adaptation revealed by systemic analyses in symbiotic bathymodiolin mussels from diverse deep-sea extreme ecosystems
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DOI：
10.1016/j.scitotenv.2024.170434
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发表时间：
2024-02-03
影响因子：
9.8
通讯作者：
Di，Yanan
中科院分区：
文献类型：
--
作者：
Xu，Jianzhou;Zhao，Ruoxuan;Di，Yanan
热液喷口和冷泉是典型的深海极端生态系统，它们具有独特的地球化学特征，为当地生物提供了独特的生存条件。一旦HV或CS停止排放，剧烈的环境变化将对深海生物构成生存风险。到目前为止，有限的知识已经了解生物的反应和适应策略的极端环境及其从活跃到灭绝阶段的过渡，主要是由于技术上的困难和缺乏代表性的生物。在这项研究中，通过两次单独的巡航从活跃和灭绝的HV（西南印度洋）或CS（南中国海）收集了深海贻贝（在多种深海极端生态系统中生存的优势和成功物种）。对贻贝鳃和消化腺进行转录组学分析，测定胁迫防御和代谢系统的多项生物学指标，并对贻贝共生体进行宏基因组学分析。结果揭示了贻贝的生态系统和组织特异性转录调控，解决了抗氧化防御，能量利用和关键化合物（如硫）代谢的自体适应。具体而言，成功的抗氧化防御有助于克服极端生态系统中普遍存在的外源性物质不可避免的代谢过程中诱导的氧化应激;代谢速率的变化有助于处理不同环境中的有毒物质;上调的硫化物：醌氧化还原酶基因表达表明，在HV和HV & CS的活跃阶段，贻贝中存在主动的硫化物解毒。细菌宏基因组分析结果表明，共生体与贻贝在能量利用、硫和碳代谢等方面存在功能补偿，是一种异源适应。两者合计，提出了一个新的见解，共生bathymodiolin贻贝将开发一个“微调”的策略相结合的自体和异源的规定，以实现高效和有效的适应成功的生存。
Hydrothermal vents (HVs) and cold seeps (CSs) are typical deep-sea extreme ecosystems with their own geochemical characteristics to supply the unique living conditions for local communities. Once HVs or CSs stop emission, the dramatic environmental change would pose survival risks to deep-sea organisms. Up to now, limited knowledge has been available to understand the biological responses and adaptive strategy to the extreme environments and their transition from active to extinct stage, mainly due to the technical difficulties and lack of representative organisms. In this study, bathymodiolin mussels, the dominant and successful species surviving in diverse deep-sea extreme ecosystems, were collected from active and extinct HVs (Southwest Indian Ocean) or CSs (South China Sea) via two individual cruises. The transcriptomic analysis and determination of multiple biological indexes in stress defense and metabolic systems were conducted in both gills and digestive glands of mussels, together with the metagenomic analysis of symbionts in mussels. The results revealed the ecosystem- and tissue-specific transcriptional regulation in mussels, addressing the autologous adaptations in antioxidant defense, energy utilization and key compounds (i.e. sulfur) metabolism. In detail, the successful antioxidant defense contributed to conquering the oxidative stress induced during the unavoidable metabolism of xenobiotics commonly existing in the extreme ecosystems; changes in metabolic rate functioned to handle toxic matters in different surroundings; upregulated gene expression of sulfide:quinone oxidoreductase indicated an active sulfide detoxification in mussels from HVs and active stage of HVs & CSs. Coordinately, a heterologous adaptation, characterized by the functional compensation between symbionts and mussels in energy utilization, sulfur and carbon metabolism, was also evidenced by the bacterial metagenomic analysis. Taken together, a new insight was proposed that symbiotic bathymodiolin mussels would develop a “finetuning” strategy combining the autologous and heterologous regulations to fulfill the efficient and effective adaptations for successful survival.