NIH Director's Pioneer Award

摘要 细胞和生物生物学中的一个基本问题是了解细胞内结构是如何 适当调整规模，以履行其基本职能。我提议探索细胞器现象。 大小，记录在发育和肿瘤发生过程中发生的变化，并调查 潜在的分子机制。我的实验室将对细胞和 胚胎发育期间细胞器的缩放，评估核、纺锤体和其他隔室 在非洲爪哇，随着直径约1毫米的卵子迅速分裂形成更小的卵裂球， 到了第15师，直径降到了40微米。哪些结构具有常量 维度，哪些维度会随着单元格变小而改变其大小？其他模式生物与癌症 对细胞进行比较，以产生对正常和异常细胞生长中细胞器比例的调查 各州。莱维氏X.laevis的细胞质卵和胚胎提取物以及与之相关的较小的热带X.tropicalis将 可用于监测核团、纺锤体和细胞室的体外伸缩。这种方法是 由于我们观察到从热带管圆线虫卵子制备的减数分裂提取物产生纺锤体 比使用相同染色体来源的莱维氏X.laevis反应缩短约30%，并且 混合实验揭示了纺锤体大小的动态、剂量依赖性调节，通过 细胞质因子。我们将确定除了纺锤体外，还有哪些细胞器是按X标度的。 Laevis和X.tropicalis提取物，并使用基于活动的分析来确定导致 观察到了差异。将测试候选因子在细胞器缩放过程中的作用 发展和癌症进展，以及应用计算方法模拟我们的 观察。这些研究将为细胞/细胞器伸缩如何有助于 细胞内形态发生和细胞分裂，这是生存和发育所必需的过程，以及 在包括癌症在内的人类疾病方面有缺陷。

ABSTRACT A fundamental problem in cell and organism biology is to understand how intracellular structures are properly scaled to carry out their essential functions. I propose to explore the phenomenon of organelle size, documenting the changes that occur during development and tumorigenesis, and investigating the underlying molecular mechanisms. My laboratory will undertake a systematic analysis of cell and organelle scaling during embryonic development, evaluating nuclei, spindles and other compartments in Xenopus laevis, as the ~1 millimeter diameter egg rapidly cleaves to form smaller blastomeres, which by the 15th division are reduced to 40 microns across. Which structures have constant dimensions, and which change their size as cells become smaller? Other model organisms and cancer cells will be compared to generate a survey of organelle scaling in normal and abnormal cell growth states. Cytoplasmic egg and embryo extracts of X. laevis and the related, smaller frog X. tropicalis will be used to monitor nuclear, spindle and cellular compartment scaling in vitro. This approach is prompted by our observation that meiotic extracts prepared from X. tropicalis eggs generate spindles that are ~30% shorter than those in X. laevis reactions using the same chromosome source, and mixing experiments have revealed a dynamic, dose-dependent regulation of spindle size by cytoplasmic factors. We will determine which organelles in addition to the spindle are scaled in X. laevis and X. tropicalis extracts, and use activity-based assays to identify the factors responsible for the observed differences. Candidate factors will be tested for their roles in organelle scaling during development and cancer progression, and computational approaches applied to model our observations. These studies will provide novel insight into how cell/organelle scaling contributes to intracellular morphogenesis and cell division, processes essential for viability and development, and defective in human diseases including cancer.