Characterization of Pollen Tube Repulsion in Arabidopsis thaliana

拟南芥花粉管斥力的表征细胞-细胞相互作用在所有真核生物的发育过程中都很重要。一个特别独特的例子涉及到迁移细胞与其路径上的细胞之间的相互作用。避免不适当的相互作用对于导航细胞到达预定目标至关重要。在人类中，这一过程的破坏会导致多精子和神经元缺陷。在植物繁殖过程中，当花粉管避开已经受精的有卵胚珠结构时，细胞回避尤为重要。然而，由于花粉管排斥发生在不透明的花结构中，这些相互作用的动态性质和介导它们的信号仍然缺乏表征。最近，一种简单的生物测定方法被开发出来，可以直接观察花粉管与胚珠的相互作用。该实验揭示了花粉管进入胚珠后不久，一个短程排斥信号被启动。利用这一发现，提出了多种细胞生物学，分子，遗传学，生化和计算方法来对模式植物拟南芥花粉管排斥进行彻底的表征。在避免虚假受精事件方面获得的见解最终可能有助于开发不能使本地物种受精的转基因花粉，这是育种者在开发转基因作物品种时必须克服的障碍。这项研究将产生新的图像分析算法，这将有利于其他迁移细胞模型，如神经元和dictyostelium，以及一个开放访问的植物繁殖教育网站，可以供教育者，学生和公众免费使用。皮马社区学院生物系教师，非博士学位。授予机构和本科生，特别是来自代表性不足的印第安人、非裔美国人和西班牙裔社区的学生，将执行本项目的部分内容。接触生物学和实践研究训练将激励他们选择科学领域的职业。

Dr. Ravishankar PalaniveluProposal #: 0723421Characterization of pollen tube repulsion in Arabidopsis thalianaCell-cell interactions are important during development of all eukaryotic organisms. One particularly unique example involves interactions between a migrating cell and those that are in its path. Avoiding inappropriate interactions is essential for a navigating cell to reach its intended target. In humans, disruption in this process results in polyspermy and neuronal defects. In plants, cell avoidance is exceptionally important during reproduction when pollen tubes avoid egg-bearing ovule structures that have already been fertilized. However, since pollen tube repulsion occurs within opaque floral structures, the dynamic nature of these interactions and the signals that mediate them remain poorly characterized. Recently, a simple biological assay was developed to directly observe pollen tube-ovule interactions. This assay revealed that a short-range repulsion signaling is initiated from an ovule soon after a pollen tube enters it. Capitalizing on this finding, a variety of cell biological, molecular, genetic, biochemical and computational approaches are proposed to conduct a thorough characterization of pollen tube repulsion in the model plant, Arabidopsis thaliana. Insights gained on avoidance of spurious fertilization events could ultimately help in developing genetically modified pollen that cannot fertilize native species, which is an impediment breeders must overcome while developing transgenic crop varieties. This study will generate novel image analysis algorithms that will benefit other migratory cell models such as neurons and dictyostelium, and an open-access educational website on plant reproduction that can be freely used by educators, students, and the public. Biology faculty from Pima Community College, a non-Ph.D. granting institution, and undergraduates, especially those from under represented Native American, African-American and Hispanic communities, will carry out parts of this project. Exposure to biology and hands-on training in research will motivate them to choose a career in science.