Data from: Genetics of gene expression responses to temperature stress in a sea urchin gene network

Stress responses play an important role in shaping species distributions and robustness to climate change. We investigated how stress responses alter the contribution of additive genetic variation to gene expression during development of the purple sea urchin, Strongylocentrotus purpuratus, under increased temperatures that model realistic climate change scenarios. We first measured gene expression responses in the embryos by RNA-seq to characterize molecular signatures of mild, chronic temperature stress. We found that an increase from 12 °C to 18 °C caused widespread alterations in gene expression including in genes involved in protein folding, RNA processing, and development. To understand the quantitative genetic architecture of this response, we then focused on a well-characterized gene network involved in endomesoderm and ectoderm specification. Using a breeding design with wild-caught individuals, we measured genetic and gene-environment interaction effects on 72 genes within this network. We found genetic or maternal effects in 33 of these genes, and that the genetic effects were correlated in the network. 14 network genes also responded to higher temperatures, but we found no significant genotype-environment interactions in any of the genes. This absence may be due to an effective buffering of the temperature perturbations within the network. In support of this hypothesis, perturbations to regulatory genes did not affect the expression of the genes that they regulate. Together, these results provide novel insights into the relationship between environmental change and developmental evolution and suggest that climate change may not expose large amounts of cryptic genetic variation to selection in this species.应激反应（Stress responses）在塑造物种分布格局与生物应对气候变化的抗逆性方面发挥着重要作用。本研究以紫海胆（Strongylocentrotus purpuratus）为研究对象，探究了在模拟现实气候变化场景的升温条件下，应激反应如何改变紫海胆发育过程中基因表达的加性遗传变异（additive genetic variation）贡献。 我们首先通过RNA-seq技术对胚胎的基因表达响应进行检测，以表征轻度慢性温度胁迫的分子特征。研究发现，温度从12℃升高至18℃会引发广泛的基因表达改变，涉及蛋白质折叠、RNA加工以及发育相关的多个基因。 为解析该响应的数量遗传结构（quantitative genetic architecture），我们后续聚焦于一个已被充分表征的、参与内中胚层（endomesoderm）与外胚层特化的基因调控网络。我们利用野生捕获个体构建的育种设计，对该网络内72个基因的遗传效应与基因-环境互作效应进行了量化测定。 结果显示，其中33个基因存在遗传效应或母体效应（maternal effects），且该网络内的遗传效应存在相关性。另有14个网络基因对升温胁迫产生了响应，但未在任何基因中检测到显著的基因型-环境互作效应。 该无显著互作的现象可能源于该调控网络对温度扰动的有效缓冲作用。为验证这一假说，我们进一步分析发现，对调控基因的扰动并未影响其调控靶基因的表达水平。 综上，本研究结果为理解环境变化与发育演化之间的关联提供了新的视角，并表明在该物种中，气候变化可能不会暴露大量隐性遗传变异（cryptic genetic variation）以供自然选择作用。