Ionic and Cytoskeletal Control of Developmental Polarity in a Plant Zygote

植物合子发育极性的离子和细胞骨架控制

• 批准号: 9506094
• 负责人: Darryl Kropf
• 金额: $ 34万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9506094&HistoricalAwards=false
• 关键词: Ionic; Cytoskeletal; Control; Developmental; Polarity

9506094 Kropf The research described in this proposal will investigate the cytoskeletal and ionic bases of polarity in zygotes of the brown alga Pelvetia. The premise in this proposal is that the acquisition of polarity is a highly regulated reorganization of the cell which will be best understood by investigating relationships between key regulatory processes. Dr. Kropf will study cytoskeletal control of polarity, and then investigate the relationship between the cytoskeleton and cytosolic regulatory ions. Preliminary evidence indicates that cortical F-actin localizes in a patch soon after fertilization, and expands into a ring that portends the future rhizoid site. Dr. Kropf hypothesizes that sperm entry induces local F-actin polymerization that then serves as a determinant of polarity, specifically marking the future rhizoid site. This hypothesis will be examined using cryofixation, confocal microscopy and TEM. Prior to mitosis, the nucleus rotates 90 degrees bringing centrosomes into an axial alignment. This nuclear rotation determines the axial orientation of the spindle and transverse alignment of the first division plane. Microtubules are thought to be primarily responsible for nuclear rotation, and their dynamic behavior during rotation will be investigated in real time by injecting zygotes with fluorescently tagged tubulin. Centrosome assembly and function will also be investigated. Finally the hypothesis that the assembly and function of cytoskeletal elements are regulated by local ion activities, specifically H+ and CA+2 activities, will be investigated. ***

9506094 Kropf 本提案中描述的研究将研究褐藻 Pelvetia 受精卵中极性的细胞骨架和离子碱基。该提议的前提是，极性的获得是细胞的高度调控的重组，通过研究关键调控过程之间的关系可以最好地理解这一点。 Kropf博士将研究细胞骨架对极性的控制，然后研究细胞骨架与胞质调节离子之间的关系。初步证据表明，受精后不久，皮质 F-肌动蛋白就定位在一个斑块中，并扩展成一个预示着未来假根位点的环。 Kropf 博士推测，精子的进入会诱导局部 F-肌动蛋白聚合，然后作为极性的决定因素，特别标记未来的假根位点。这一假设将通过冷冻固定、共焦显微镜和 TEM 进行检验。在有丝分裂之前，细胞核旋转 90 度，使中心体轴向排列。该核旋转决定了主轴的轴向方向和第一分割平面的横向对准。微管被认为主要负责核旋转，并且通过向受精卵注射荧光标记的微管蛋白，可以实时研究它们在旋转过程中的动态行为。还将研究中心体的组装和功能。最后，将研究细胞骨架元件的组装和功能受局部离子活性（特别是 H+ 和 CA+2 活性）调节的假设。 ***