Elucidating the genomic basis of fitness variation in a long-lived polymorphic predator

野生物种的适应度变异通常取决于许多复杂的性状，因此很难从生态学和分子机制上理解。与这种假定的总体情况相反，一些进化枝的适应性主要与一个简单的特征有关。这种情况存在于普通的秃鹰和许多其他鹰目猛禽中。在这里，基因编码的颜色形态是终生繁殖成功的主要决定因素，具有孟德尔遗传模式，对应于一个位点和两个等位基因。我们的长期数据集显示，秃鹫的颜色变化与许多可能导致不同适应度的特征相关，包括宿主-寄生虫相互作用、免疫防御、迁徙和攻击行为。这提供了三种可能的假设，说明这些相关性是如何产生的：黑化通路成员基因内的单核苷酸多态性（SNP）影响不同的性状。2. 2 .相互作用伙伴中的几个snp具有多效性效应，包括黑色素化和其他性状；染色体倒位将功能不相关的基因及其依赖性状之间的变异联系起来。本项目将使用基因组工具为这些假设之一收集决定性证据，并以自上而下的方法解决所有猛禽和秃鹰作为焦点物种的颜色多态性和适应性变化。该项目的第一步将使用多个平台对长链读段和链接读段进行测序，以及光学制图，以构建不同秃鹫形态的染色体水平参考基因组。作为副产品，这种杂交组合将产生一种非常有价值和罕见的基因组资源——与疟疾相关的秃鹰血液寄生虫toddi白细胞虫的基因组。这些高质量的参考基因组将作为许多普通秃鹰个体和其他多态和单态猛禽代表的短读序列的定位目标。结果数据将用于全基因组关联研究和基于单基因的选择分析，详细揭示秃鹰的形态和适合度变化对应的基因组区域，以及秃鹰血寄生虫和其他猛禽类群的一般模式。最终，该项目将揭示造成秃鹰颜色多态性的基因组区域，并将预测由于多效性或连锁而与颜色相关的性状。此外，我们将发现多态性是否在多个实例中出现，或者这种基因组变异是否在猛禽序列中普遍存在，并在它们的快速物种形成中发挥了关键作用。

Fitness variation in wild species commonly depends on many complex traits and is therefore hard to understand in terms of ecological and molecular mechanisms. In contrast to this presumed general picture, fitness in some clades mainly correlates with one simple trait. Such a case is present in the common buzzard Buteo buteo and many other bird of prey of the order Accipitriformes. Here, the genetically encoded colour morph is the major determinant of lifetime reproductive success and has a Mendelian inheritance pattern, corresponding to one locus with two alleles. Our long-term datasets show that colour morph in buzzards correlates with many traits which may contribute to the differential fitness, including host-parasite interactions, immune defences, migration and aggressive behavior. This provides three alternative hypotheses how these correlations can arise: 1. A single nucleotide polymorphism (SNP) within a member gene of the melanisation pathway affects different traits. 2. Several SNPs within interaction partners having pleiotropic effects on melanisation and other traits and 3. A chromosomal inversion linking variation among functionally unrelated genes and their dependent traits. This project will use genomic tools to gather decisive evidence for one of these hypotheses and address the colour polymorphism and fitness variation in all birds of prey and the common buzzard as a focal species in a top-down approach. The first step of the project will use multiple platforms for sequencing long and linked reads, as well as optical mapping, to construct chromosome-level reference genomes of the different buzzard morphs. The hybrid assembly will produce, as a by-product, a highly valuable and rare genomic resource - the genome of the malaria-related blood parasite of buzzards, Leucocytozoon toddi. The high-quality reference genomes will be used as mapping targets for short-read sequences from many individuals of common buzzard and representatives of other polymorphic and monomorphic birds of prey. The resulting data will be deployed in genome-wide association studies and singleton-based selection analyses, revealing the genomic regions corresponding to morph and fitness variation in buzzards in detail, but also in their blood parasites and in other raptor taxa as a general pattern. Eventually, this project will reveal the genomic regions responsible for the colour polymorphism in common buzzards and will predict the traits which should correlate with colour because of pleiotropy or linkage. Furthermore, we will discover whether polymorphisms have arisen on multiple instances or whether this genomic variation is universal in the order of raptors and has played a key role for their fast speciation.