Genetics of Differences Between the Mating Systems of Mimulus guttatus and M. nasutus

小行星9727578 数量性状基因座（QTL）的鉴定和分析为直接评价植物进化的遗传基础提供了有力的工具 可繁殖生物体之间的差异。 一个进化的转变 植物，提供了一个独特的机会，以解决遗传基础， 适应是从异交中进化出的自花受精， 可能是被子植物中最常见的进化转变。 的 属Mimulus（玄参科），其中许多密切相关， 能育的物种或种群，提供了一个很好的模型系统， 研究自花受精和物种形成的进化。 共同 在Mimulus guttatus物种复合体中的黄色猴花可以说是 最多型和最迅速发展的成员属，和 不同的种群在自花受精的程度上差异很大。 拟议的研究有两个具体目标。 首先，我们建议进行彻底的遗传分析的花的差异之间的一个 Mimulus guttatus的主要异交群体和高度自交群体 为了确定是否有大的基因， 这两种效应导致了这些物种之间的极端花型差异。 这一目标将通过绘制数量性状图谱来实现 影响花形态的基因座，使用高分辨率的连锁图， 基于微卫星、AFLP和RAPD标记的Mimulus基因组。 二是 建议测试数量性状基因座是否影响花性状 与自交相关的基因会直接影响 自然种群中的自花受精。 这一目标将 通过在田间分析渗入的自交率来完成 包含M的行。nasutus等位基因为一个M.点滴状 背景 这些实验将解决长期存在的和基本的问题，即突变对生物进化的作用。 适应 例如，新达尔文进化论的一个基本主张 是自然选择作用于非常微小的表型差异， 一个人口中的个体。 如果这种细微的个体差异 遗传成分，那么适应将导致稳定的固定， 影响小的基因 相反，其他人认为，适应 通常是由极少数遗传位点的剧烈变化引起的。 这些 实验将有助于回答诸如此类的基本问题。 他们将 也有助于我们理解 自花受精和其他形式的近亲繁殖在自然和 驯化的动植物种群。

9727578 Willis The identification and analysis of quantitative trait loci (QTLs) offers a powerful tool with which to assess directly the genetic basis of evolved differences between interfertile organisms. One evolutionary transition in plants that offers a unique opportunity to address the genetic basis of adaptations is the evolution of self-fertilization from outcrossing, which is perhaps the most frequent evolutionary transition in angiosperms. The genus Mimulus (Scrophulariaceae), within which are many closely related and interfertile species or populations, provides an excellent model system for studying the evolution of self-fertilization and speciation. The common yellow monkeyflowers in the Mimulus guttatus species complex are arguably the most polytypic and most rapidly evolving members of the genus, and populations vary tremendously in terms of the degree of self-fertilization. There are two specific goals of the proposed study. First, we propose to conduct a thorough genetic analysis of the floral differences between a primarily outcrossing population of Mimulus guttatus and a highly selfing population of Mimulus nasutus in order to determine whether genes of large effect contribute to the extreme floral differences between these species. This goal will be accomplished through the mapping of quantitative trait loci affecting floral morphology using a high-resolution linkage map of the Mimulus genome based on microsatellite, AFLP, and RAPD markers. Second, we propose to test whether quantitative trait loci affecting floral traits that are correlated with selfing actually have direct effects on the rate of self-fertilization in a natural population. This goal will be accomplished by analyzing in the field the selfing rates of introgression lines containing a M. nasutus allele for floral QTLs in a M. guttatus background. These experiments will address long-standing and fundamental questions about the role of mutations of large effect on the evolution of adaptations. For example, a fundamental claim of neo-Darwinian evolution is that natural selection acts on very slight phenotypic differences among individuals in a population. If this subtle individual variation has a genetic component, then adaptations will result from the steady fixation of genes of small effect. Conversely, others have argued that adaptation frequently results from drastic changes at a very few genetic loci. These experiments will help to answer basic questions such as this. They will also contribute to our basic understanding of how and why self-fertilization and other forms of inbreeding evolve in natural and domesticated populations of plants and animals.