DISSERTATION RESEARCH: Between-class gene flow in complex mating systems: The evolution of breeding systems in Silene vulgaris

在大多数植物和动物中，雄性和雌性在大小、形状或颜色上都不同，因为自然选择驱使两性朝着不同的方向发展。这种二态性的进化受到交配过程中雄性和雌性之间基因混合的限制，这种混合被称为类间基因流动。本研究研究了一种植物Silene vulgaris中雌雄同体或雌性个体间基因流动的影响。在具有如此复杂的交配系统的物种中，不同种群间的基因流动速率不同，这使得它们的影响更容易被发现。利用遗传标记，本工作将估计雌雄同体和雌性的自然选择强度，以及多种群中雌雄同体和雌性之间的基因流动模式。这些估计值将与遗传率估计值相结合，以确定阶级之间的基因流动是否限制了性别差异的进化。这项工作将测试阶级间基因流动作为影响自然系统适应的一个因素的重要性。对这一过程的理解将为农业上重要物种的人工选择策略提供信息，如牛（Bos primigenius），其中雄性和雌性具有不同的期望性状，以及具有复杂交配系统的物种，如玉米（Zea mays）。最后，这项工作直接支持了博士生作为研究员和导师的培养，并为本科生从事数量遗传学和分子生态学的研究提供了机会。

In most plants and animals, males and females differ in size, shape, or color because natural selection drives the sexes in different directions. The evolution of this dimorphism is constrained by the mixing of genes among males and females during mating known as between-class gene flow. This work investigates the effects of between-class gene flow in a plant Silene vulgaris, in which individuals are either hermaphrodite or female. In species with such complex mating systems, the rates of between-class gene flow vary among populations, allowing their effects to be more easily detected. Using genetic markers, this work will estimate the strength of natural selection in hermaphrodites and females, as well as the patterns of gene flow among hermaphrodites and females for multiple populations. These estimates will be combined with estimates of heritability to determine if between-class gene flow limits the evolution of differences between sexes.This work will test the importance of between-class gene flow as a factor affecting adaptation in natural systems. The understanding of this process will inform strategies for artificial selection of agriculturally important species such as cattle (Bos primigenius), in which males and females have different desired traits, and species with complex mating systems, such as maize (Zea mays). Finally, this work directly supports the training of a doctoral student as a researcher and mentor and provides opportunities for undergraduate students to engage in research in quantitative genetics and molecular ecology.