Phenotypic plastic responses allow organisms to rapidly adjust when facing environmental challenges—these responses comprise morphological, behavioral but also life‐history changes. Alteration of life‐history traits when exposed to predation risk have been reported often in the ecological and genomic model organism Daphnia. However, the molecular basis of this response is not well understood, especially in the context of fish predation. Here, we characterized the transcriptional profiles of two Daphnia galeata clonal lines with opposed life histories when exposed to fish kairomones. First, we conducted a differential gene expression, identifying a total of 125 candidate transcripts involved in the predator‐induced response, uncovering substantial intraspecific variation. Second, we applied a gene coexpression network analysis to find clusters of tightly linked transcripts revealing the functional relations of transcripts underlying the predator‐induced response. Our results showed that transcripts involved in remodeling of the cuticle, growth, and digestion correlated with the response to environmental change in D. galeata. Furthermore, we used an orthology‐based approach to gain functional information for transcripts lacking gene ontology (GO) information, as well as insights into the evolutionary conservation of transcripts. We could show that our candidate transcripts have orthologs in other Daphnia species but almost none in other arthropods. The unique combination of methods allowed us to identify candidate transcripts, their putative functions, and evolutionary history associated with predator‐induced responses in Daphnia. Our study opens up to the question as to whether the same molecular signature is associated with fish kairomones‐mediated life‐history changes in other Daphnia species.

中文翻译：

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洞悉水蚤捕食者诱导反应的遗传基础

表型可塑性反应使有机体在面对环境挑战时能够快速适应-这些反应包括形态，行为以及生命历史的变化。在生态和基因组模型生物水蚤中，经常有生活史特征发生变化的风险。但是，这种反应的分子基础尚不十分清楚，特别是在鱼类捕食的情况下。在这里，我们表征了两个水蚤的转录特征暴露于鱼类海洛酮中时具有相反生活史的无性系。首先，我们进行了差异基因表达，确定了与捕食者诱导的反应有关的总共125个候选转录本，发现了大量的种内变异。其次，我们应用了基因共表达网络分析来发现紧密链接的转录物簇，揭示了捕食者诱导的反应背后的转录物的功能关系。我们的结果表明，与表皮重塑，生长和消化有关的转录本与D对环境变化的响应相关。 加莱塔塔。此外，我们使用了基于语言学的方法来获取缺少基因本体（GO）信息的转录本的功能信息，以及对转录本进化保护的见解。我们可以证明我们的候选转录本在其他水蚤物种中具有直系同源物，而在其他节肢动物中却几乎没有。独特的方法组合使我们能够识别与水蚤捕食者诱导的反应有关的候选转录本，其推定功能以及进化史。我们的研究提出了一个问题，即相同的分子标记是否与其他水蚤物种中的鱼海rom酮介导的生活史变化相关。