Song Jingwei, McDowell Jan R
Virginia Institute of Marine Science (VIMS) College of William and Mary Gloucester Point VA USA.
Ecol Evol. 2020 Dec 28;11(3):1352-1367. doi: 10.1002/ece3.7138. eCollection 2021 Feb.
Resilience to climate change depends on a species' adaptive potential and phenotypic plasticity. The latter can enhance survival of individual organisms during short periods of extreme environmental perturbations, allowing genetic adaptation to take place over generations. Along the U.S. East Coast, estuarine-dependent spotted seatrout () populations span a steep temperature gradient that provides an ideal opportunity to explore the molecular basis of phenotypic plasticity. Genetically distinct spotted seatrout sampled from a northern and a southern population were exposed to acute cold and heat stress (5 biological replicates in each treatment and control group), and their transcriptomic responses were compared using RNA-sequencing (RNA-seq). The southern population showed a larger transcriptomic response to acute cold stress, whereas the northern population showed a larger transcriptomic response to acute heat stress compared with their respective population controls. Shared transcripts showing significant differences in expression levels were predominantly enriched in pathways that included metabolism, transcriptional regulation, and immune response. In response to heat stress, only the northern population significantly upregulated genes in the apoptosis pathway, which could suggest greater vulnerability to future heat waves in this population as compared to the southern population. Genes showing population-specific patterns of expression, including , , , and , are candidates for future studies aiming to monitor intraspecific differences in temperature stress responses in spotted seatrout. Our findings contribute to the current understanding of phenotypic plasticity and provide a basis for predicting the response of a eurythermal fish species to future extreme temperatures.
对气候变化的适应能力取决于一个物种的适应潜力和表型可塑性。后者可以在极端环境扰动的短时期内提高个体生物的存活率，使遗传适应在几代人之间发生。在美国东海岸，依赖河口生存的斑点海鲈（）种群跨越了一个陡峭的温度梯度，这为探索表型可塑性的分子基础提供了一个理想的机会。从北部和南部种群中采集的基因不同的斑点海鲈暴露于急性冷应激和热应激（每个处理组和对照组有5个生物学重复），并使用RNA测序（RNA-seq）比较它们的转录组反应。与各自种群的对照组相比，南部种群对急性冷应激表现出更大的转录组反应，而北部种群对急性热应激表现出更大的转录组反应。在表达水平上显示出显著差异的共享转录本主要富集在包括代谢、转录调控和免疫反应的途径中。在热应激反应中，只有北部种群在凋亡途径中显著上调基因，这可能表明与南部种群相比，该种群对未来热浪的脆弱性更大。显示出种群特异性表达模式的基因，包括、、和，是未来旨在监测斑点海鲈温度应激反应种内差异的研究的候选基因。我们的研究结果有助于当前对表型可塑性的理解，并为预测广温性鱼类物种对未来极端温度的反应提供了基础。
