NIH Director's Pioneer Award

摘要 细胞和有机体生物学的一个基本问题是了解细胞内结构是如何 适当调整以执行其基本功能。我打算探索细胞器现象 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进行系统分析， 胚胎发育期间的细胞器缩放，评估细胞核、纺锤体和其他隔室 在非洲爪蟾中，当直径约1毫米的卵快速分裂形成更小的卵裂球时， 到第15次分割时，其宽度减小到40微米。哪些结构具有常数 尺寸，以及随着细胞变小而改变其大小？其他模式生物和癌症 细胞将被比较，以生成正常和异常细胞生长中的细胞器缩放的调查 states.卵和胚的细胞质提取物。laevis和相关的较小的青蛙X。热带意志 可用于体外监测细胞核、纺锤体和细胞区室的缩放。这种方法 提示我们的观察，减数分裂提取物制备的X。热带蚁卵产生纺锤体 比X染色体短30%使用相同的染色体来源的laevis反应，和 混合实验揭示了纺锤体大小的动态的、剂量依赖性的调节， 细胞质因子我们将确定除了纺锤体之外，哪些细胞器在X中缩放。 laevis和X.热带提取物，并使用基于活性的测定，以确定负责的因素， 观察差异。候选因子将在细胞器缩放过程中测试其作用。 发展和癌症进展，以及应用于模拟我们的 意见。这些研究将为细胞/细胞器缩放如何有助于 细胞内形态发生和细胞分裂，对生存力和发育至关重要的过程， 包括癌症在内的人类疾病中的缺陷。

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.