Yan Guoyong, Wei Tong, Lan Yi, Xu Ting, Qian Peiyuan
Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China.
Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China.
Integr Zool. 2024 Jul 27. doi: 10.1111/1749-4877.12881.
Acute environmental changes cause stress during conventional deep-sea biological sampling without in situ fixation and affect gene expressions of samples collected. However, the degree of influence and underlying mechanisms are hardly investigated. Here, we conducted comparative transcriptomic analyses between in situ and onboard fixed gills and between in situ and onboard fixed mantles of deep-sea mussel Gigantidas haimaensis to assess the effects of incidental sampling stress. Results showed that transcription, translation, and energy metabolism were upregulated in onboard fixed gills and mantles, thereby mobilizing rapid gene expression to tackle the stress. Autophagy and phagocytosis that related to symbiotic interactions between the host and endosymbiont were downregulated in the onboard fixed gills. These findings demonstrated that symbiotic gill and nonsymbiotic mantle responded differently to sampling stress, and symbiosis in the gill was perturbed. Further comparative metatranscriptomic analysis between in situ and onboard fixed gills revealed that stress response genes, peptidoglycan biosynthesis, and methane fixation were upregulated in the onboard fixed endosymbiotic Gammaproteobacteria inside the gills, implying that energy metabolism of the endosymbiont was increased to cope with sampling stress. Furthermore, comparative analysis between the mussel G. haimaensis and the limpet Bathyacmaea lactea transcriptomes resultedidentified six transcription factor orthologs upregulated in both onboard fixed mussel mantles and limpets, including sharply increased early growth response protein 1 and Kruppel-like factor 5. They potentially play key roles in initiating the response of sampled deep-sea macrobenthos to sampling stress. Our results clearly show that in situ fixed biological samples are vital for studying deep-sea environmental adaptation.
在传统的深海生物采样过程中，若不进行原位固定，急性环境变化会导致压力产生，并影响所采集样本的基因表达。然而，影响程度及潜在机制鲜有研究。在此，我们对深海贻贝海马底栖大贻贝原位固定与船上固定的鳃以及原位固定与船上固定的外套膜进行了比较转录组分析，以评估偶然采样压力的影响。结果表明，船上固定的鳃和外套膜中，转录、翻译和能量代谢上调，从而调动快速基因表达来应对压力。与宿主和内共生体之间共生相互作用相关的自噬和吞噬作用在船上固定的鳃中下调。这些发现表明，共生鳃和非共生外套膜对采样压力的反应不同，鳃中的共生关系受到干扰。进一步对原位固定与船上固定的鳃进行比较宏转录组分析发现，鳃内船上固定的内共生γ-变形菌中，应激反应基因、肽聚糖生物合成和甲烷固定上调，这意味着内共生体的能量代谢增加以应对采样压力。此外，对贻贝海马底栖大贻贝和帽贝乳白深海帽贝转录组的比较分析确定了在船上固定的贻贝外套膜和帽贝中均上调的六个转录因子直系同源物，包括早期生长反应蛋白1和类 Kruppel 样因子5急剧增加。它们可能在启动采样的深海大型底栖生物对采样压力的反应中起关键作用。我们的结果清楚地表明，原位固定的生物样本对于研究深海环境适应性至关重要。
