EASTBIO (WCUB) Speciation and sex-biased gene expression in butterflies

EASTBIO (WCUB) 蝴蝶的物种形成和性别偏向基因表达

• 批准号: 2112020
• 金额: --
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2112020
• 关键词: EASTBIO; WCUB; Speciation; sex; biased; EASTBIO; WCUB; Speciation; sex; biased

Although males and females share most of their genome, their biology differs in fundamental ways. Sexually dimorphic traits are under intense natural and sexual selection favouring opposing optima in males and females. Studies in model systems like Drosophila have shown that over 50% of genes show sex biased or sex limited expression and it is thought that sex-biased expression has evolved to resolve sexually antagonistic selection (Ellegren & Parsch 2007).Recent empirical work has shown that sex-biased genes evolve at faster rates and - as predicted by theoretical models - are concentrated on the sex-chromosomes in a number of organisms (Ellegren & Parsch 2007). However, we still know very little about how quickly sex-biased gene expression evolves as species diverge and what knock-on effects the distinct evolutionary dynamics of sex-biased genes have on the speciation process. For example, an intriguing possibility is that sex-specific genes, by virtue of their faster rates of evolution, potential involvement in sexual selection and linkage to sex chromosomes may disproportionately trigger reproductive isolation in the early stages of speciation. Comparative studies suggest that rates of speciation may indeed be correlated with levels of sexually antagonistic evolution. However, genome-wide data on gene-expression are limited to a small number of model systems and we currently lack any direct comparison between sex-specific and unbiased genes in terms of the relevant forces that act during the speciation process. Studies on female heterogametic systems (e.g. birds and butterflies) are particularly valuable, because contrasting them with male heterogametic organisms allows us to find out what mechanisms cause sex-biased genes to accumulate on the sex-chromosomes (Huylmans et al 2017). The aim of the project is to use sister-species of European butterflies as a model to quantify both sex-biased and species-specific gene expression and investigate the interplay between gene expression, selection and gene-flow during speciation.The specific aims are to:i) Measure the turn-over in sex-specific expression during species divergence.ii) Compare the evolutionary dynamics during species divergence between sex biased genes and unbiased genes by fitting explicit models of the speciation process (Lohse et al. 2016).iii) Test whether butterfly Z chromosomes are enriched for male-biased genes as expected if positive selection at sex-biased genes is driven by dominant mutations.The lead supervisor, Konrad Lohse, brings extensive experience in population genetics, insect speciation and bioinformatics and has developed inference methods to model divergence and gene flow from genomic data. In collaboration with LepBase and Alex Hayward (Exeter University), the Lohse lab is generating reference assemblies genome-wide polymorphism data for several sister species pairs of European butterflies. Co-supervisor Mike Ritchie has extensive experience with designing RNASeq experiments and speciation research. The student will obtain state of the art training in genomics, bioinformatics and advanced evolutionary genetics and statistics. This will also involve basic training through EastBio workshops as well as tailored bioinformatics and coding workshops offered by Edinburgh Genomics. This project is mainly computational/quantitative but also includes some fieldwork and/or a short spell in the wet-lab to generate RNASeq data.

尽管男性和女性共享大部分基因组，但其生物学以基本方式不同。性二态性状受到强烈的自然和性选择，有利于男性和女性中对立的最佳选择。像果蝇这样的模型系统中的研究表明，超过50％的基因表现出性别有偏见或性别有限的表达，并且人们认为，性偏见的表达已经发展为解决性拮抗作用的选择（Ellegren＆Parsch 2007）。经验性工作表明，性偏见的基因在FERASTER率和类型的模型中所占据的模型 - 集中在某种程度上 - 集中在某种程度上 - 集中在某种程度上 - 遍及该模型，而这些模型占据了一项繁殖 - （Ellegren＆Parsch 2007）。但是，我们仍然对性偏见的基因表达的速度随着物种的差异的发展以及性偏见基因对物种形成过程的独特进化动力学的影响而了解的速度知之甚少。例如，一种有趣的可能性是，特定于性别的基因由于其更快的进化速度，潜在地参与性选择以及与性染色体联系的可能性可能不成比例地触发物种早期阶段的生殖隔离。比较研究表明，形成率确实可以与性拮抗剂进化水平相关。但是，关于基因表达的全基因组数据仅限于少数模型系统，目前，就形成过程中起作用的相关力而言，性别特异性基因和无偏基因之间的直接比较。对女性异元系统（例如鸟类和蝴蝶）的研究特别有价值，因为将它们与男性异型生物体形成鲜明对比，使我们能够找出哪些机制会导致性别偏见的基因积聚在性染色体上（Huylmans等人，2017年）。该项目的目的是使用欧洲蝴蝶的姐妹种类作为模型来量化性偏见和物种特异性基因表达，并研究物种形成过程中基因表达，选择和基因流的相互作用之间的相互作用。具体目的是：i）在物种差异过程中衡量性别及其在差异过程中的跨性别的转化。形成过程的显式模型（Lohse等人，2016）.III）测试是否会像预期的那样对男性偏见的基因进行蝴蝶Z Z染色体，如果性别偏见的基因的肯定选择是由主要突变驱动的，则主要主管的主要主管，Konrad Lohse，Konrad Lohse，Konrad Lohse在种群中及其基因遗传学，昆虫疾病的经验和基因构成方法，并具有基因侵害，并具有昆虫疾病，并具有昆虫疾病，并具有昆虫疾病，并具有基因侵蚀性，并具有基因侵蚀性，并具有基因侵蚀性的侵害。来自基因组数据。 Lohse Lab与Lepbase和Alex Hayward（埃克塞特大学）合作，为几种欧洲蝴蝶对的几种姊妹物种对生成了参考组装全基因组多态性数据。共同参与者Mike Ritchie在设计RNASEQ实验和物种研究方面拥有丰富的经验。该学生将获得基因组学，生物信息学和高级进化遗传学和统计学的最先进培训。这还将涉及通过Eastbio研讨会以及爱丁堡基因组学提供的量身定制的生物信息学和编码研讨会的基础培训。该项目主要是计算/定量，但还包括一些现场工作和/或湿lab中的简短咒语以生成RNASEQ数据。