Johnson Kevin M, Hofmann Gretchen E
Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803 USA.
Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106-9620 USA.
Conserv Physiol. 2020 Mar 26;8(1):coaa013. doi: 10.1093/conphys/coaa013. eCollection 2020.
The ecologically important thecosome pteropods in the complex have recently been the focus of studies examining the impacts global change factors - e.g., ocean acidification (OA) and ocean warming (OW) - on their performance and physiology. This focus is driven by conservation concerns where the health of pteropod populations is threatened by the high susceptibility of their shells to dissolution in low aragonite saturation states associated with OA and how coupling of these stressors may push pteropods past the limits of physiological plasticity. In this manipulation experiment, we describe changes in the transcriptome of the Antarctic pteropod, , to these combined stressors. The conditions used in the laboratory treatments met or exceeded those projected for the Southern Ocean by the year 2100. We made two general observations regarding the outcome of the data: (1) Temperature was more influential than pH in terms of changing patterns of gene expression, and (2) these Antarctic pteropods appeared to have a significant degree of transcriptomic plasticity to respond to acute abiotic stress in the laboratory. In general, differential gene expression was observed amongst the treatments; here, for example, transcripts associated with maintaining protein structure and cell proliferation were up-regulated. To disentangle the effects of OA and OW, we used a weighted gene co-expression network analysis to explore patterns of change in the transcriptome. This approach identified gene networks associated with OW that were enriched for transcripts proposed to be involved in increasing membrane fluidity at warmer temperatures. Together these data provide evidence that has a limited capacity to acclimate to the combined conditions of OA and OW used in this study. This reduced scope of acclimation argues for continued study of how adaptation to polar aquatic environments may limit the plasticity of present-day populations in responding to future environmental change.
该群落中具有重要生态意义的有壳翼足类动物最近成为了研究全球变化因素（如海洋酸化（OA）和海洋变暖（OW））对其性能和生理影响的焦点。这种关注是出于保护方面的考虑，因为翼足类动物种群的健康受到其贝壳在与OA相关的低文石饱和度状态下易溶解的高敏感性以及这些压力源的耦合可能如何使翼足类动物超出生理可塑性极限的威胁。在这个操纵实验中，我们描述了南极翼足类动物对这些综合压力源的转录组变化。实验室处理中使用的条件达到或超过了预计到2100年南大洋的条件。关于数据结果我们有两个总体观察结果：（1）在基因表达变化模式方面，温度比pH更具影响力；（2）这些南极翼足类动物在实验室中似乎具有显著程度的转录组可塑性以应对急性非生物胁迫。一般来说，在各处理之间观察到了差异基因表达；例如，在这里，与维持蛋白质结构和细胞增殖相关的转录本上调。为了厘清OA和OW的影响，我们使用加权基因共表达网络分析来探索转录组的变化模式。这种方法识别出了与OW相关的基因网络，这些网络富含被认为参与在较高温度下增加膜流动性的转录本。这些数据共同提供了证据，表明该翼足类动物对本研究中使用的OA和OW综合条件的适应能力有限。这种适应范围的缩小表明需要继续研究对极地水生环境的适应如何可能限制当今种群对未来环境变化做出反应的可塑性。
