Pérez-Portela Rocío, Riesgo Ana, Wangensteen Owen S, Palacín Cruz, Turon Xavier
Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, and Research Institute of Biodiversity (IRBIO), Barcelona, Spain.
Center for Advanced Studies of Blanes (CEAB, CSIC), Girona, Spain.
Mol Ecol. 2020 Sep;29(17):3299-3315. doi: 10.1111/mec.15564. Epub 2020 Aug 21.
Information about the genomic processes underlying responses to temperature changes is still limited in non-model marine invertebrates. In this sense, transcriptomic analyses can help to identify genes potentially related to thermal responses. We here investigated, via RNA-seq, whole-transcriptomic responses to increased and decreased temperatures in a thermophilous keystone sea urchin, Arbacia lixula, whose populations are increasing in the Mediterranean. This species is a key driver of benthic communities' structure due to its grazing activity. We found a strong response to experimentally induced cold temperature (7°C), with 1,181 differentially expressed transcripts relative to the control condition (13°C), compared to only 179 in the warm (22°C) treatment. A total of 84 (cold treatment) and three (warm treatment) gene ontology terms were linked to the differentially expressed transcripts. At 7°C the expression of genes encoding different heat shock proteins (HSPs) was upregulated, together with apoptotic suppressor genes (e.g., Bcl2), genes involved in the infection response and/or pathogen-recognition (e.g., echinoidin) and ATP-associated genes, while protein biosynthesis and DNA replication pathways were downregulated. At 22°C neither HSPs induction nor activation of the previously mentioned pathways were detected, with the exception of some apoptotic-related activities that were upregulated. Our results suggest a strong transcriptional response associated with low temperatures, and support the idea of low water temperature being a major limitation for A. lixula expansion across deep Mediterranean and northern Atlantic waters.
在非模式海洋无脊椎动物中，关于温度变化反应背后的基因组过程的信息仍然有限。从这个意义上说，转录组分析有助于识别可能与热反应相关的基因。我们通过RNA测序研究了一种嗜热的关键海胆——刺冠海胆（Arbacia lixula）对温度升高和降低的全转录组反应，该海胆在地中海的种群数量正在增加。由于其摄食活动，该物种是底栖生物群落结构的关键驱动因素。我们发现，与对照条件（13°C）相比，实验诱导的低温（7°C）引发了强烈反应，有1181个差异表达转录本，而在高温（22°C）处理中只有179个。共有84个（低温处理）和3个（高温处理）基因本体术语与差异表达转录本相关。在7°C时，编码不同热休克蛋白（HSP）的基因表达上调，同时凋亡抑制基因（如Bcl2）、参与感染反应和/或病原体识别的基因（如海胆素）以及与ATP相关的基因也上调，而蛋白质生物合成和DNA复制途径则下调。在22°C时，未检测到HSP的诱导或上述途径的激活，只有一些与凋亡相关的活动上调。我们的结果表明与低温相关的强烈转录反应，并支持低温是刺冠海胆在地中海深处和北大西洋水域扩张的主要限制因素这一观点。
