DISSERTATION RESEARCH: Identification and Characterization of Incompatibility Genes that Contribute to Postzygotic Reproductive Isolation Between Species of Mimulus

当一个物种分裂成两个或更多繁殖隔离的种群时，物种形成就会发生。这些后代物种之间生殖隔离屏障的进化对于防止基因交换和保存物种差异是至关重要的。到目前为止，很少有研究确定哪些基因会导致生殖隔离。这项建议侧重于一种交配后的生殖隔离，即杂交不育，这种不育被认为是通过积累当它们在物种杂交中聚集在一起时不相容的基因变化而进化出来的。这项拟议的研究将调查导致猴花属两个近缘物种Mimulus guttatus和M.nasutus之间杂交雄性不育的简单遗传不亲和性。本项目的目标是克隆这些杂交不育基因，并鉴定它们的发育和分子功能。建立Mimulus“物种形成基因”的分子身份和功能将是理解形成物种分化的进化力量的重要一步。此外，这项拟议的研究将详细分析微花和花粉发育的协调和时间安排，这是研究花的适应和物种形成的模式系统。该项目还将为高中生和本科生提供开展协作实验室研究的机会。

Speciation occurs when a single species splits into two or more reproductively isolated populations. The evolution of reproductive isolating barriers among these descendent species is essential to prevent gene exchange and preserve species differences. Thus far, few studies have identified which genes cause reproductive isolation. This proposal focuses on one type of post-mating reproductive isolation, hybrid sterility, which is thought to evolve by an accumulation of genetic changes that are incompatible when they come together in species hybrids. The proposed research will investigate a simple genetic incompatibility that causes hybrid male sterility between two closely related species of monkeyflower, Mimulus guttatus and M. nasutus. The objectives of this project are to clone these hybrid sterility genes and to characterize their developmental and molecular functions. Establishing the molecular identities and functions of Mimulus "speciation genes" will be an important step towards understanding the evolutionary forces that shape species divergence. Furthermore, the proposed research will provide a detailed analysis of the coordination and timing of flower and pollen development in Mimulus, a model system for studies of floral adaptation and speciation. This project will also provide opportunities for high school and undergraduate students to conduct collaborative laboratory research.