The functional impacts of structural genomic variation on life-history evolution

确定适应性表型性状的遗传基础是现代进化生物学的一个主要焦点。到目前为止，这项工作集中在单个碱基对的变化上，称为单核苷酸多态性。然而，基因组是一个更复杂的，个体，种群和物种之间的许多差异是以结构变化的形式存在的。例如，这些可以是基因的复制，基因组部分的缺失或某些区域方向的变化。虽然这种结构遗传变异很多，被认为是遗传多样性的一个重要方面，但人们对它们如何促进适应性进化知之甚少。造成这一根本性知识差距的主要原因是，直到最近才广泛获得研究这种结构变化的技术。在我的奖学金中，我将使用新的技术和分析方法来剖析结构遗传变异在适应性进化中的功能作用。我将把这些应用到一个令人兴奋和理想的系统中，即欧洲七鳃鳗生活史策略的分歧。欧洲七鳃鳗属于无颌脊椎动物的原始谱系，它们表现出三种不同的成年生活史：1）迁移到海洋中寄生在其他鱼类身上，然后返回河流产卵并死亡; 2）迁移到淡水湖泊中寄生在河流产卵并死亡之前;或3）它们在家乡河流中保持整个成年生活，并迅速成熟，产卵和死亡，而不作为成年人进食。这些不同的生活史在整个欧洲都很普遍，经常可以在同一条河流中共存，甚至杂交，从而提供了一个强大的系统来识别它们进化背后的遗传差异。我将确定区分这些生活史形式的结构变异，并确定它们的进化影响与单核苷酸变化的不同。此外，为了了解结构变异如何导致适应性表型的变化，我将研究它们对不同组织中基因调控变异的影响。因此，拟议的研究将大大有助于回答我们对进化的机械理解中的一个基本知识缺口：结构遗传变异对适应性进化有多重要？

Identifying the genetic basis of adaptive phenotypic traits is a major focus of modern evolutionary biology. To date, this work has concentrated on changes in individual base pairs, called single nucleotide polymorphisms. Yet, genomes are a more complex, and many differences between individuals, populations and species are in the form of structural changes. For example, these can be duplications of genes, deletions of parts of the genome or changes in the direction of certain regions. While such structural genetic variants are numerous and thought to be a crucial aspect of genetic diversity, very little is known about how they contribute to adaptive evolution. The main reason for this fundamental knowledge gap is that technologies to study such structural changes have not been widely accessible until recently. In my Fellowship, I will use novel technologies and analytical approaches to dissect the functional role of structural genetic variants in adaptive evolution. I will apply these to an exciting and ideal system, the divergence in life-history strategies in European lampreys. European lampreys belong to a primitive lineage of jawless vertebrates that show up to three distinct adult life histories: they either 1) migrate into the ocean to feed parasitically on other fish, before returning to rivers to spawn and die; 2) migrate into freshwater lakes to feed parasitically before returning rivers to spawn and die; or 3) they remain their entire adult life in their home river, and rapidly mature, spawn and die, without ever feeding as adults. These alternative life histories are widespread across Europe and can often be found to co-exist in the same river and even interbreed, thus providing a powerful system to identify the genetic differences underlying their evolution. I will identify structural variants that distinguish these life-history forms and determine how their evolutionary impact differs from single nucleotide changes. Furthermore, to understand how structural variants lead to changes in adaptive phenotypes, I will investigate their impact on gene regulatory variant in different tissues. Thereby, the proposed research will strongly contribute to answering a fundamental knowledge gap in our mechanistic understanding of evolution: how important are structural genetic variants for adaptive evolution?