Production d'omble de fontaine adaptée aux changements climatiques: évaluation de l'importance des effets épigénétiques

本研究项目的目的是为建立鱼类生产方法提供科学依据，以支持小溪鳟鱼休闲渔业（Salvelinus fontinalis），这将适应气候变化导致的新环境背景。结合表观遗传变异和基因表达的研究，结合生理信息的获取和表型适应度的组成部分，在进化定量遗传学的概念框架下进行解释的目标有三个：1)测试成虫性成熟和子代孵化过程中的热状态对表观遗传变化的影响，这些变化可能影响成虫幼年期的生存、生长和对热变化的抵抗力；2)通过因子交叉设计，估计跨代可塑性的遗传力和基因-环境互作对这些表型性状变异的影响，以及表观遗传机制和生理性能相关基因的表达；3)评估野生放养后鳟鱼生产过程中温度变化对甲基化模式持久性、生长、存活和遗传力的影响。该项目将为养鱼业和政府机构的合作伙伴提供准确的知识，了解养殖和孵化温度条件对表观遗传修饰的影响及其对养殖后代性能的影响。这些知识将有助于为生产和饲养制定有效的繁殖和孵化计划，这些计划将更好地适应当前和未来的热条件。该项目还将有助于更深入地了解表观遗传过程的机制，特别是阐明哪些表型响应跨代表观遗传传递，从而阐明这些机制在水生物种适应潜力中的重要性。最终，这些知识将有助于更好地预测对气候变化的适应潜力。

The objective of this research project is to provide the scientific basis for the establishment of fish production methods aiming to support the brook trout recreational fisheries (Salvelinus fontinalis), which will be adapted to the new environmental context resulting from climate change. Three objectives integrating the study of epigenetic variation and gene expression combined with the acquisition of physiological information and components of phenotypic fitness and interpreted in the conceptual framework of evolutionary quantitative genetics are targeted: 1) testing the effect of thermal regime during adult sexual maturation and offspring incubation on epigenetic changes that may affect survival, growth and resistance to thermal variation during development of young stages of life; 2) estimating, through a factorial crossing design, the heritability and gene-environment interactions of transgenerational plasticity effects on the variation of these phenotypic traits as well as the expression of genes involved in epigenetic mechanisms and physiological performance; 3) assessing the effects of changes in the thermal regime during the production of brook trout on the persistence of methylation patterns, growth, survival and heritability of these traits following stocking in the wild. This project will provide our partners from fish farming industry and government agencies with accurate knowledge of the consequences of breeding and incubation thermal conditions on epigenetic modifications and their impacts on the performance of farmed offspring. This knowledge will allow to develop efficient reproductive and incubation schemes for production and stocking, which will be better adapted to current and future thermal conditions. This project will also contribute to a deeper understanding of the mechanisms underlying epigenetic processes, in particular to elucidate which phenotypes respond to transgenerational epigenetic transmission and thus clarify the importance of these mechanisms in the adaptive potential of aquatic species. Ultimately, this knowledge will help better predict adaptation potential to climate change.