Microtubule-Associated Proteins and the Regulation of Microtubule Organization During Oogenesis and Early Development in Xenopus laevis

大量证据表明，微管在两个重要的发育轴的建立中起着重要的作用，这两个轴是在受精卵分裂之前指定或建立的：卵母细胞和卵的动物-植物（A-V）轴，以及发育中的胚胎的背-腹侧（D-V）轴。本实验旨在探讨微管相关蛋白（MAPs）在非洲爪蟾卵母细胞和胚胎中A-V轴和D-V轴形成过程中调控微管组装和组织的作用。从爪蟾卵中分离出三个生物化学上不同的XMAPs。共聚焦显微镜和电子显微镜将用于检查XMAPs在卵子发生和早期发育期间的分布。XMAPs和XMAP抗体的显微注射将用于探测这些蛋白在卵母细胞、卵子和胚胎中的功能。XMAP磷酸化对微管组装的影响将在体外和通透性卵母细胞和卵子中进行研究。最后，利用分子克隆技术研究XMAPs与其他物种的MAPs之间的结构关系。该项目的结果将为微管在细胞和胚胎极性形成中的作用提供新的信息。本项目将以蛙卵母细胞、卵子和胚胎为模型系统，研究细胞骨架网络（即微管）的调控。该项目的研究结果将为早期发育过程中细胞极性和胚胎极性的建立机制提供信息。因此，这个项目应该提供对建立生物体身体计划的机制的见解。＊＊＊

MCB 9506051 David Gard Substantial evidence suggests that microtubules play important roles in the establishment of two important developmental axes that are specified or established prior to the cleavage of fertilized amphibian eggs: the animal-vegetal (A-V) axis of oocytes and eggs, and the dorsal-ventral (D-V) axis of the developing embryo. The proposed experiments investigate the role that microtubule-associated proteins (MAPs) play in regulating microtubule assembly and organization during formation of the A-V and D-V axes in Xenopus oocyte and embryos. Three biochemically-distinct XMAPs have been isolated from Xenopus eggs. Confocal and electron microscopy will be used to examine the distribution of XMAPs during oogenesis and early development. Microinjection of XMAPs and XMAP antibodies will be used to probe the function of these proteins in oocytes , eggs, and embryos. The effects of XMAP phosphorylation on microtubule assembly will be addressed in vitro and in permeabilized oocytes and eggs. Finally, molecular cloning will be used to examine the structural relationship between XMAPs and MAPs from other species. Results from this project will provide new information on the role of the microtubules in the formation of cellular and embryonic polarity. %%% This project will examine the regulation of a cytoskeletal network (i.e., microtubules) using oocytes, eggs, and embryos of the frog as a model system. Results from this project will provide information on mechanisms establishing cellular polarity and embryonic polarity during early development. Consequently, this project should provide insights into the mechanisms that establish the body plan of an organism. ***