College of Fisheries and Life Science, Dalian Ocean University, Dalian, 116023, China.
Engineering Research Center of Shellfish Culture and Breeding in Liaoning Province, Dalian Ocean University, Dalian, 116023, China.
BMC Genomics. 2020 Apr 23;21(1):318. doi: 10.1186/s12864-020-6734-6.
Hypoxia is an important environmental stressor in aquatic ecosystems, with increasingly impacts on global biodiversity. Benthic communities are the most sensitive parts of the coastal ecosystem to eutrophication and resulting hypoxia. As a filter-feeding organism living in the seafloor sediment, Ruditapes philippinarum represents an excellent "sentinel" species to assess the quality of marine environment. In order to gain insight into the molecular response and acclimatization mechanisms to hypoxia stress in marine invertebrates, we examined hypoxia-induced changes in immune-related gene expression and gene pathways involved in hypoxia regulation of R. philippinarum.
We investigated the response of the Manila clam R. philippinarum to hypoxia under experimental conditions and focused on the analysis of the differential expression patterns of specific genes associated with hypoxia response by RNA-seq and time course qPCR analysis. A total of 75 genes were captured significantly differentially expressed, and were categorized into antioxidant/oxidative stress response, chaperones/heat shock proteins, immune alteration, and cell proliferation/apoptosis. Fourteen hypoxia responsive genes were validated significantly up/down regulated at different time 0, 2, 5, and 8 d in gills of R. philippinarum in hypoxia challenged group. Functional enrichment analysis revealed the HIF signaling pathway and NF-κB signaling pathway play pivotal roles in hypoxia tolerance and resistance in R. philippinarum.
The HIF signaling pathway and NF-κB signaling pathway play a critical role in hypoxia tolerance and resistance in Manila clam. The immune and defense related genes and pathways obtained here gain a fundamental understanding of the hypoxia stress in marine bivalves and provide important insights into the physiological acclimation, immune response and defense activity under hypoxia challenge. The reduced metabolism is a consequence of counterbalancing investments in immune defense against other physiological processes.
缺氧是水生生态系统中的一个重要环境胁迫因素，对全球生物多样性的影响日益增加。底栖生物群落是沿海生态系统对富营养化和由此产生的缺氧最敏感的部分。作为一种生活在海底沉积物中的滤食性生物，菲律宾蛤仔代表了评估海洋环境质量的极好的“哨兵”物种。为了深入了解海洋无脊椎动物对低氧胁迫的分子反应和适应机制，我们研究了低氧胁迫对菲律宾蛤仔免疫相关基因表达和低氧调节相关基因途径的影响。
我们在实验条件下研究了菲律宾蛤仔对低氧的反应，并通过 RNA-seq 和时间过程 qPCR 分析重点分析了与低氧反应相关的特定基因的差异表达模式。共捕获到 75 个显著差异表达的基因，并分为抗氧化/氧化应激反应、伴侣/热休克蛋白、免疫改变和细胞增殖/凋亡。在低氧胁迫组菲律宾蛤仔鳃中，有 14 个低氧应答基因在不同时间 0、2、5 和 8d 时被验证为显著上调/下调。功能富集分析表明，HIF 信号通路和 NF-κB 信号通路在菲律宾蛤仔的低氧耐受和抵抗中起关键作用。
HIF 信号通路和 NF-κB 信号通路在菲律宾蛤仔的低氧耐受和抵抗中起关键作用。本研究获得的免疫和防御相关基因和途径，为海洋双壳类动物的低氧胁迫提供了基本的认识，并为低氧胁迫下的生理适应、免疫反应和防御活动提供了重要的见解。代谢减少是免疫防御对其他生理过程的投资的结果。
