Microtuble Organization and Dynamics During Amphibian Oogenesis

两栖类的卵沿着动物-植物（A-V）轴沿着极化 由色素和蛋黄的不对称分布定义， 纺锤体的位置。 A-V轴形成于 卵子发生在胚胎的形成过程中起着重要的作用 在胚胎发育后期。 微管和 微管组织中心常常与 A-V轴的规格，尽管精确的机制仍然存在 未知 所提出的实验旨在确定 微管的组织和动力学 卵子发生和房室轴形成过程中的组织中心 非洲爪蟾 共聚焦免疫荧光显微镜将是 用于检查组织的总和乙酰化（非- 动态）微管。 微量注射 生物素化微管蛋白将被用于表征微管 在A-V轴期间，I期卵母细胞的组装位点和动力学 在III-IV期和卵母细胞成熟期间形成。 荧光素标记微管蛋白的显微注射和时间推移 共聚焦显微镜将用于检查微管动力学， 活的I期卵母细胞和在组装和排列期间， 减数分裂纺锤体 %%% 非洲爪蟾的卵母细胞是一个大的球形细胞， 细胞质成分的非随机分布 在其发展过程中。 控制这一切的机制 重新分配是未知的，但意义重大，因为它 是胚胎两极化生长的基础 该项目将 提供有关微管作用的重要信息， 微管组织的中心是动物的形成 这种细胞的植物轴。

Amphibian eggs are polarized along an animal-vegetal (A-V) axis defined by the asymmetric distribution of pigment and yolk, and by the location of the meiotic spindles. The A-V axis formed during oogenesis plays an important role in the establishment of the germ layers during later embryonic development. Microtubules and microtubule organizing centers have often been implicated in specification of the A-V axis, though the precise mechanism remains unknown. The proposed experiments are designed to determine the organization and dynamics of microtubules and microtubule organizing centers during oogenesis and A-V axis formation in Xenopus laevis. Confocal immunofluorescence microscopy will be used to examine the organization of total and acetylated (non- dynamic) microtubules during oogenesis. Microinjection of biotinylated-tubulin will be used to characterize the microtubule assembly sites and dynamics in stage I oocytes, during A-V axis formation in stages III-IV, and during oocyte maturation. Microinjection of fluorescein-labeled tubulin and time-lapse confocal microscopy will be used to examine microtubule dynamics in living stage I oocytes and during assembly and alignment of the meiotic spindles. %%% The oocyte of Xenopus laevis is a large spherical cell that exhibits a nonrandom distribution of cytoplasmic components early in its development. The mechanism that controls this redistribution is not known, but is significant because it underlies polarized growth of the embryo. This project will provide important information on the roles of microtubules and microtubule organizing centers on the formation of the animal- vegetal axis of this cell.