RUI: The genetics and mathematical modeling of pollen performance

开花植物在繁殖上不是不分青红皂白的。换句话说，在繁殖过程中，一些花粉有更大的交配成功率。花粉表现的差异通常在花粉竞争中表现出来，长期以来被认为具有重要的进化意义和农业意义。虽然有丰富的工作历史集中在导致花粉表现差异的进化压力上，但我们缺乏对这一过程的功能遗传理解。在这里，研究人员将利用模式植物拟南芥来定义指导花粉表现的遗传因素，并利用新的显微镜分析来量化花粉竞争的过程。定义花粉表现的遗传学和花粉竞争过程的建模将改变我们未来用弹性和选择性授粉系统智能修改作物品种的能力。这项工作将由本科生进行，他们将通过建立采用跨学科方法的现场多人指导科学团队来参与增强的研究经验。在生物学家和数学家的双重指导下，学生团队将协调实验计划、数据收集和数学建模，以完成本提案的研究目标，并参与芝加哥和印第安纳州西北部学校的K-12推广活动。因此，这个项目为大量的本科生和K-12学生提供了将数学思维融入基础生物学问题的机会，并在合作小组中这样做，其中许多学生来自科学界代表性不足的群体。这样的工作有很大的潜力让学生接触和从事研究工作。研究人员先前已经使用重组自交系和全基因组关联图谱来确定影响拟南芥花粉表现的主要位点。此外，他们还开发了一种显微镜方法，可以在竞争期间对单个花粉群体的行为进行可视化和量化。这种方法提供了量化花粉竞争过程中不同花粉表现如何指导非随机交配的机会，因为花粉管在竞争将精子输送到卵子时留下了它们的运动、速率和行为的可见痕迹。在这个项目中，研究人员将鉴定和表征负责花粉差异表现的基因，以及它们的自然变异如何影响花粉竞争过程。这些数据首次提供了对花粉竞争过程进行数学建模所需的工具。这项工作将为花粉性能如何影响花粉竞争、花粉干扰、非随机交配和受精过程提供更深入的机制理解。这一发现的进化意义超越了植物；精子竞争过程和花粉竞争过程之间有着深刻的相似之处，但对两者都没有强有力的物理模型。这项研究提供了一个独特的机会来定义基因变异和行为之间的联系，这些行为可以指导非随机交配，这是一个在有性生物中具有巨大进化意义的过程。

Flowering plants are not reproductively indiscriminate. In other words, during reproduction, some pollen have greater mating success. Differences in pollen performance, often revealed during pollen competition, have long been recognized as evolutionarily significant and agriculturally important. While there is a rich history of work focused on the evolutionary pressures that lead to differential pollen performance, we lack a functional genetic understanding of the process. Here, the researchers will exploit the model plant Arabidopsis thaliana to define the genetic elements that direct pollen performance, and utilize new microscopy assays to quantify the process of pollen competition. Defining the genetics of pollen performance and modeling the process of pollen competition will transform our ability to intelligently modify crop varieties with resilient and selective pollination systems in the future. This work will be conducted by undergraduate students who will participate in an enhanced research experience through the establishment of on-site multiply-mentored scientific teams that employ an interdisciplinary approach. Student teams, duel mentored by a biologist and mathematician, will coordinate experimental planning, data collection and mathematical modeling to accomplish the research goals of this proposal, and also participate in K-12 outreach to schools in Chicago and Northwest Indiana. Thus, this project offers a large number of undergraduate and K-12 students, many from underrepresented groups in science, the opportunity to integrate mathematical thinking into questions of basic biology, and to do so in collaborative groups. Such work has great potential to expose and recruit students to research professions.The researchers have previously used recombinant inbred lines and genome-wide association mapping to identify the major loci that influence pollen performance in Arabidopsis thaliana. Additionally, they have developed a microscopy approach that allows the visualization and quantification of the behavior of individual pollen populations during competitions. This approach offers the opportunity to quantify how differential pollen performance during pollen competition directs nonrandom mating, as pollen tubes leave a visible trace of their movements, rates and behaviors as they compete to deliver sperm to eggs. In this project, the researchers will identify and characterize the genes responsible for differential pollen performance and how their natural variation influences the process of pollen competition. These data provides, for the first time, the tools needed to mathematically model the process of pollen competition. This work will provide a deeper mechanistic understanding of how pollen performance influences pollen competition, pollen interference, nonrandom mating and the process of fertilization. The evolutionary significance of this extends beyond plants; there are deep parallels between the well-studied process of sperm competition and pollen competition, yet there are not robust physical models for either. This study represents a unique opportunity to define the connections between variation in genes and behaviors that can direct nonrandom mating, a process of immense evolutionary significance in sexual organisms.