Molecular evolution of sex and reproduction related genes and their role in speciation: The genomic architecture of hybrid male sterility

性和生殖相关基因的分子进化及其在物种形成中的作用：杂种雄性不育的基因组结构

• 批准号: 235-2013
• 负责人: Singh, Rama
• 金额: $ 2.4万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=631764
• 关键词: Molecular; evolution; sex; reproduction; related

Summary of the Proposal Understanding speciation, the evolutionary process of how new species form and give rise to the spectacular diversity of living organisms, is a central problem in evolutionary biology. Our understanding of speciation has been greatly advanced by using genetic and molecular approaches and over a dozen large-effects 'speciation genes' have been identified in many model organisms. The major remaining question is to understand how the functions of these speciation genes relate to the processes of genomic divergence during speciation. Investigation of the causal connections between the molecular evolution of sex and reproduction related (SRR) genes, sexual selection, and speciation among species of the Drosophila melanogaster complex form the core of our research program. Two conceptual advances form the basis of our research proposal. First, SRR genes are known to evolve faster, with male-biased genes evolving faster compared to female-biased genes. It is interesting to know that many of the known 'speciation genes' are characterized as SRR genes, all of which show signatures of rapid evolution. Second, it is expected that mutations affecting interspecific incompatibility would evolve from being minor to major as a result of the increasing number of incompatibilities caused by subsequent mutations over time. Using detailed gene expression studies with Drosophila and their hybrids, we propose to test two major hypotheses: (1) that the major, large-effects 'speciation genes' are a subset of rapidly evolving SRR genes, and (2) that during the speciation process, minor-effects speciation genes evolve into major-effects alleles as a result of a 'snowball effect', i.e. the increasing number of gene incompatibilities of subsequent mutations over time. The significance of these findings lies at the forefront of speciation research in deciphering the patterns of molecular evolution of SRR genes and relating them to genetic and ecological processes of speciation.

理解物种形成的提案的摘要，即新物种如何形成并引起生物的壮观多样性的进化过程，是进化生物学的核心问题。通过使用遗传和分子方法以及在许多模型生物中已经确定了数十个大效应的“物种基因”，我们对物种形成的理解已经大大提高了。剩下的主要问题是了解这些物种基因的功能与物种过程中基因组差异的过程如何相关。研究性别与繁殖相关的分子进化（SRR）基因，性选择和种种物种之间的因果关系的研究，果蝇Melanogaster复合物中的物种形成了我们研究计划的核心。两个概念进步构成了我们研究建议的基础。首先，已知SRR基因的发展速度更快，与雌性偏见的基因相比，男性偏见的基因进化更快。有趣的是，许多已知的“物种基因”都被描述为SRR基因，所有这些基因均显示出快速进化的特征。其次，预计影响种间不相容性的突变将从次要到主要的变化，这是由于随后的突变随着时间的推移而导致的不相容性的增加。 Using detailed gene expression studies with Drosophila and their hybrids, we propose to test two major hypotheses: (1) that the major, large-effects 'speciation genes' are a subset of rapidly evolving SRR genes, and (2) that during the speciation process, minor-effects speciation genes evolve into major-effects alleles as a result of a 'snowball effect', i.e. the increasing number of gene随着时间的流逝，随后的突变不兼容。这些发现的重要性在于物种研究的最前沿，解释了SRR基因分子演化的模式，并将其与物种的遗传和生态过程有关。