The evolution of metabolic adaptation to environmental change

伴随环境变化而来的生态和进化转变通常涉及饮食的改变和随之而来的形态适应。这些变化得到了充分的研究和理解。令人惊讶的是，在野生物种中，尽管能量学对生物体功能至关重要，并且这些知识对农业和水产养殖具有潜在价值，但处理饮食变化所需的遗传编码代谢修饰在很大程度上是未知的（Tocher 2010水产养殖资料）。许多鱼类从咸水到淡水的主要转变需要许多进化适应，最明显的是渗透调节。不太为人所知的是，脂肪酸是所有脊椎动物的重要饮食资源，既是有机成分，也是代谢能量的来源，但它在淡水系统中的可用性远低于海洋系统。脂肪酸可利用性和代谢变化的生态重要性才刚刚认识到（Twininget al. 2021 Ecol.Lett.）。太平洋棘鱼的淡水定殖在具有Fads2基因复制的谱系中得到促进，Fads2基因参与必需-3脂肪酸的合成（Ishikawa et al. 2019 Science）。尽管有强有力的证据表明，大西洋刺鱼谱系在淡水中定居的能力也各不相同（Dean et al. 2019 moll . biol . evolution .），但人们对大西洋中这种重复的发生知之甚少。更普遍的是，尽管在棘鱼中已知了几个有希望的遗传候选者，但人们对处理脂肪酸可用性限制所需的代谢变化网络知之甚少。该项目将量化饮食脂肪酸限制对大西洋棘鱼的影响，并研究脂肪酸代谢如何依赖于一些关键的进化和遗传变化。这将提高我们对生物体如何通过新陈代谢的改变来应对环境变化的能量后果的理解。

The ecological and evolutionary transitions that accompany environmental change often involve alterations in diet and accompanying morphological adaptations. These changes are abundantly well researched and understood. Surprisingly, the genetically encoded metabolic modifications requiredto deal with dietary change are largely unknown in wild species, despite the fundamental importance of energetics for organismal function and the potential value of such knowledge to agriculture and aquaculture (Tocher 2010 Aquaculture Res.). The major transition from salt- to freshwater effected by numerous fish species demands many evolutionary adaptations, most obviously in osmoregulation. Less well known is that fatty acids,which are a critical dietary resource for all vertebrates, both as organic constituents and sources of metabolic energy, are much less available in freshwater than in marine systems. The ecological importance of variation in fatty acid availability and metabolism is only just being realised (Twininget al. 2021 Ecol.Lett.). Colonisation of freshwater by Pacific stickleback is facilitated in lineages that possess duplications of a gene, Fads2, involved in the synthesis of essential -3 fatty acids (Ishikawa et al. 2019 Science). Despite strong evidence that Atlantic stickleback lineages also vary in their ability to colonise freshwater (Dean et al. 2019 Mol.Biol.Evol.), little is known about the occurrence of this duplication in the Atlantic. More generally, little is known about the network of metabolic changes required to deal with restriction of fatty acid availability, despite several promising genetic candidates being known in stickleback.This project will quantify the consequences of dietary fatty acid restriction in Atlantic stickleback and investigate how fatty acid metabolism depends on a number of key evolutionary, genetic changes. This will improve our understanding of how organisms deal with the energetic consequences of environmental change through alterations in metabolism.