Nutrient levels in coastal environments have been increasing globally due to elevated inputs of sewage and terrigenous sediments carrying fertilizers. Yet, despite their immense filtering capacities, marine sponges appear to be less affected by elevated nutrients than sympatric benthic organisms, such as corals. While the molecular-level stress response of sponges to elevated seawater temperatures and other toxicants has been defined, this study represents the first global gene expression analysis of how sponges respond to elevated nitrogen. Gene correlation network analysis revealed that sponge gene modules, coded by colours, became either highly upregulated (Blue) or downregulated (Turquoise, Black, Brown) as nitrogen treatment levels increased. Gene Ontology enrichment analysis of the different modules revealed genes involved in cell signalling, immune response and flagella motility were affected by increasing nitrogen levels. Notably, a decrease in the regulation of NF-kappaB signalling and an increase in protein degradation was identified, which is comparable to metabolic pathways associated with the sponge thermal stress response. These results highlight that Cymbastela stipitata can rapidly respond to changes in the external environment and identifies pathways that probably contribute to the ability of C. stipitata to tolerate short-term nutrient pulses.

中文翻译：

---

基因相关网络揭示了在光合海绵中对升高的氮的转录组反应。

由于增加的污水和携带肥料的陆源沉积物的投入，全球沿海环境的营养水平一直在增加。然而，尽管具有巨大的过滤能力，但海洋海绵似乎比同属底栖生物（例如珊瑚）受养分增加的影响较小。尽管已经定义了海绵对海水温度升高和其他有毒物质的分子水平应力响应，但这项研究代表了海绵对高氮反应的首次全球基因表达分析。基因相关网络分析表明，随着氮处理水平的提高，海绵基因模块由颜色编码，变得高度上调（蓝色）或下调（绿松石，黑色，棕色）。对不同模块的基因本体论富集分析揭示了参与细胞信号传导的基因，氮水平的升高会影响免疫反应和鞭毛运动。值得注意的是，已确定了NF-κB信号传导调节的减少和蛋白质降解的增加，这与与海绵热应激反应相关的代谢途径相当。这些结果表明，Cymbastela stipitata可以快速响应外部环境的变化，并确定可能有助于C. stipitata耐受短期营养脉冲能力的途径。