Collaborative Research: RoL: Rapid Evolution of Reproductive Isolation via Hybrid Seed Lethality in Mimulus

生活形式分化为900万个不同的物种，取决于血统在生殖上变得孤立。这种生殖隔离阻止了杂交，允许出现不同的物种。这项研究项目利用了猴花(Mimulus)中存在的巨大物种多样性。对这一组中的许多物种进行比较，将揭示造成生殖隔离的基因变化和进化力量。了解导致物种多样化的遗传机制和进化过程之间的相互作用也将有助于农业育种计划。该项目包括努力教育小学生和高中生了解进化和物种多样性的价值，并培训本科生和研究生学习进化生物学和发育的分子遗传学。本研究项目侧重于F1杂交种子不活力的进化，这是一种相对未被研究但可能是开花植物中常见的生殖障碍。该项目集成了系统发育、种群遗传、发育、转录和基因组作图方法，系统地研究了杂交种子失败是否是推动整个Mimulus属种群和物种多样化的关键隔离机制。该项目将测试这样一种假设，即这种形式的生殖隔离通过在所有近亲繁殖的开花植物物种中由亲子冲突产生的自然选择而迅速演变。这种冲突驱动的选择有望通过差异基因组印迹导致不同谱系种子胚乳发育的遗传控制的不同进化，迅速导致强烈的合子后隔离，而不管物种所经历的生态环境。该项目的主要目标是确定杂交种子丧失活力的进化速度、强度和重要性；评估杂交种子丧失活力的发育机制和转录特征，并最终确定杂交种子丧失活力的遗传基础和该物种物种形成遗传基础的平行程度。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The divergence of living forms into nine million different species depends on lineages becoming reproductively isolated. This reproductive isolation prevents interbreeding, allowing for the emergence of distinct species. This research project makes use of the tremendous species diversity present in the monkey flowers (Mimulus). Comparison of many pairs of species in this group will uncover the genetic changes responsible for and the evolutionary forces at work that generated reproductive isolation. Understanding the interactions between genetic mechanisms and evolutionary processes that lead to species diversification will also contribute to agricultural breeding programs. The project includes efforts to educate grade school and high school students about evolution and the value of species diversity, and train undergraduate and graduate students in evolutionary biology and the molecular genetics of development.This research project focuses on the evolution of F1 hybrid seed inviability, a relatively unstudied but potentially common reproductive barrier in flowering plants. This project integrates phylogenetic, population genetic, developmental, transcriptomic, and genome mapping approaches to systematically address whether hybrid seed failure is a key isolating mechanism driving population and species diversification across the genus Mimulus. The project will test the hypothesis that this form of reproductive isolation evolves rapidly via natural selection generated by parent-offspring conflict in all outbreeding flowering plant species. Such conflict-driven selection is expected to cause divergent evolution of the genetic control of endosperm development in seeds in different lineages via differential genomic imprinting, quickly leading to strong postzygotic isolation regardless of the ecological environments that the species experience. The main goals of this project are to determine the rate of evolution, strength, and importance of hybrid seed inviability in the speciation process across the genus Mimulus; to assess the developmental mechanisms and transcriptomic signatures of hybrid seed inviability, and finally to determine the genetic basis of hybrid seed inviability and the degree of parallelism in the genetic basis of speciation in this genus.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.