Sex and speciation: molecular evolution of sexual dimorphism and mechanisms of speciation

性别与物种形成：性二态性的分子进化和物种形成机制

• 批准号: 235-2007
• 负责人: Singh, Rama
• 金额: $ 4.91万
• 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: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=449066
• 关键词: Sex; speciation; molecular; evolution; sexual

For many decades, the problem of speciation has been refractory to detailed genetic analyses, however with the availability of an increasing number of sequenced genomes, expression data and transgenic methodology, the scientific community is now in a position to understand the origins and evolution of species. During the last tenure of our NSERC grant, our studies were specifically directed towards understanding molecular evolution of sex- and reproduction-related genes and their role in speciation. We showed that genes involved in reproduction are evolving faster than genes with other functions, and that sexual function (male-/female-biased) and chromosomal location (sex vs. non-sex) are major factors influencing rapid gene evolution. Our goal in the next phase is to use modern molecular methodology to to test the hypothesis that variation and evolution of sexual system genes through their effects on sexual dimorphism are responsible for the development of reproductive isolation and speciation. Large scale gene expression studies of sterile interspecific hybrids have highlighted the importance of regulatory sequences in controlling gene expression and their role in speciation. We will analyse the evolution of cis-regularory sequences involved in sex-, tissue- and developmental stage-specific functions. Transgenics, using coding an regulatory sequences of different species for selected candidate genes will be done. Finally, with a view to link molecules to morphology and to unravel the dynamics of natural and sexual selection for a sexual a trait, we have undertaken a comprehensive study of the evolution of the male sexual trait, the sex combs, in Drosophila species. Studies involving artificial selection, behavioural experiments and gene expression profiles of selected lines will provide an understanding of the evolutionary dynamics of this sexual trait which has evolved rapidly and independently in different groups of Drosophila species. The results will shed light on the origins of species as well as on the evolution of sexual system genes and the tempo of change during speciation.

几十年来，物种形成问题一直难以进行详细的遗传分析，然而，随着越来越多的基因组测序、表达数据和转基因方法的可用性，科学界现在能够了解物种的起源和进化。在NSERC资助的最后一个任期内，我们的研究专门针对理解性和生殖相关基因的分子进化及其在物种形成中的作用。我们发现，与生殖有关的基因比具有其他功能的基因进化得更快，而性功能（男性/女性倾向）和染色体位置（性别与非性别）是影响基因快速进化的主要因素。我们下一阶段的目标是使用现代分子方法来验证这样的假设，即性系统基因的变异和进化通过它们对两性二态性的影响来负责生殖隔离和物种形成的发展。对不育种间杂交种的大规模基因表达研究强调了调控序列在控制基因表达及其在物种形成中的作用。我们将分析涉及性别、组织和发育阶段特定功能的顺式调节序列的进化。转基因，通过编码不同物种的调控序列来选择候选基因将被完成。最后，为了将分子与形态学联系起来，并揭示性特征的自然和性选择动力学，我们对果蝇物种的雄性性特征——性梳的进化进行了全面的研究。涉及人工选择、行为实验和选定品系基因表达谱的研究将提供对这种性特征的进化动力学的理解，这种性特征在不同种类的果蝇物种中迅速而独立地进化。这些结果将揭示物种的起源，以及性系统基因的进化和物种形成过程中变化的速度。