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

阐明长寿多态性捕食者适应性变异的基因组基础

• 批准号: 433069365
• 负责人: Dr. Nayden Chakarov
• 金额: --
• 依托单位: Arbeitsgruppe Verhaltensforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/433069365?language=en
• 关键词: Elucidating; genomic; basis; fitness; variation

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.

野生物种的适应度变异通常取决于许多复杂的性状，因此很难从生态和分子机制方面理解。与这一假定的总体情况相反，某些进化枝的适应性主要与一个简单的特征相关。这种情况存在于普通鵟和许多鹰形目猛禽中。在这里，基因编码的颜色变形是一生繁殖成功的主要决定因素，并且具有孟德尔遗传模式，对应于一个基因座有两个等位基因。我们的长期数据集显示，秃鹰的颜色变形与许多可能导致适应性差异的特征相关，包括宿主与寄生虫的相互作用、免疫防御、迁徙和攻击行为。这提供了这些相关性如何产生的三种替代假设： 1. 黑化途径成员基因内的单核苷酸多态性 (SNP) 影响不同的性状。 2. 相互作用伙伴内的几个 SNP 对黑化和其他性状具有多效性作用，以及 3. 染色体倒位，将功能上不相关的基因及其相关性状之间的变异联系起来。该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普通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进行测序以及光学图谱，以构建不同秃鹰形态的染色体水平参考基因组。作为副产品，杂交组装将产生一种非常有价值且稀有的基因组资源——与疟疾相关的秃鹰血液寄生虫托迪白细胞虫的基因组。高质量的参考基因组将用作普通秃鹰和其他多态性和单态猛禽代表的短读序列的定位目标。所得数据将用于全基因组关联研究和基于单例的选择分析，详细揭示与秃鹰的形态和适应度变异相对应的基因组区域，以及它们的血液寄生虫和其他猛禽类群的一般模式。最终，该项目将揭示负责普通秃鹰颜色多态性的基因组区域，并预测因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目中普遍存在，并在它们的快速物种形成中发挥了关键作用。