The Cytoskeleton and Polarity in Pollen Development

9726968 Brown本项目将继续进行高等植物花粉形态发生中细胞骨架的光镜和电镜研究。该项目将比较三个系统的花粉发育：兰花（兰科），草（禾本科）和莎草（莎草科）。每一种发育中的花粉细胞都表现出一套复杂但有特点的减数分裂和有丝分裂、核运动和其他事件，这些事件建立了极化或不对称的花粉结构。基于对正常事件的详细描述，设计了微管或肌动蛋白阵列受到干扰的实验，以评估这些细胞骨架元件在决定花粉发育模式中的作用。细胞将暴露于各种已知影响微管或肌动蛋白丝的药物（秋水仙碱、细胞松弛素D）、特定抗体（抗γ微管蛋白、抗整合素）和其他药物中，以破坏那些似乎参与花粉形成过程中特定细胞事件的细胞骨架元件。我们还将进行实验来检验细胞凋亡的作用。该项目将提供高等植物花粉发育的基本比较信息，并将记录细胞骨架决定细胞极性和组织不对称的基本机制。＊＊＊

9726968 Brown This project is to continue light and electron microscopic studies on the role of the cytoskeleton in pollen morphogenesis in higher plants. The project will be a comparison of pollen development in three systems: orchids (Orchidaceae), grasses (Poaceae) and sedges (Cyperaceae). The developing pollen cells of each exhibit a complex but characteristic set of meiotic and mitotic divisions, nuclear movements, and other events that establish polarized or asymmetric pollen structures. Based on detailed descriptions of normal events, experiments are designed in which either the microtubule or actin arrays are perturbed to assess the role these cytoskeletal elements play in determining the developmental patterns of the pollen. Cells will be exposed to various drugs (colchicine, cytochalasin D) known to affect microtubules or actin filaments, specific antibodies (anti-gamma tubulin, anti-integrins) and other agents in order to disrupt those cytoskeletal elements which appear to be involved in specific cellular events during pollen formation. Experiments will also be undertaken to examine the role of apoptosis. The project will provide fundamental comparative information on pollen development in higher plants and will document basic mechanisms by which the cytoskeleton determines cell polarity and tissue asymmetry. ***