The evolution of metabolic adaptation to environmental change

伴随着环境变化的生态和进化转变往往涉及饮食的改变和伴随的形态适应。人们对这些变化进行了充分的研究和理解。令人惊讶的是，应对饮食变化所需的基因编码的代谢修饰在野生物种中基本上是未知的，尽管能量学对生物功能的基本重要性以及这种知识对农业和水产养殖的潜在价值(Tocher 2010水产养殖研究)。由许多鱼类物种影响的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关键膳食资源，无论是作为有机成分还是代谢能量来源，在淡水中的可获得性比在海洋系统中要少得多。人们刚刚意识到脂肪酸供应和新陈代谢变化的生态重要性(Twininget al.2021生态。让我们。)。太平洋刺鱼在拥有Fads2基因重复的谱系中促进淡水的定居，Fads2基因参与合成必需的-3脂肪酸(Ishikawa等人)。2019科学)。尽管有强有力的证据表明，大西洋刺鱼血统在它们定居淡水的能力上也有所不同(Dean等人。2019 Mol.Biol.Evol)，人们对这种复制在大西洋发生的情况知之甚少。更广泛地说，人们对处理脂肪酸供应限制所需的代谢变化网络知之甚少，尽管已知有几个有希望的候选基因在刺鱼身上。该项目将量化大西洋刺鱼饮食脂肪酸限制的后果，并调查脂肪酸代谢如何依赖于一些关键的进化和基因变化。这将提高我们对生物体如何通过新陈代谢的变化来处理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.