ANALYSIS AND CONTROL OF CHROMOSOME MOVEMENT

染色体运动的分析和控制

• 批准号: 3268551
• 负责人: R. BRUCE NICKLAS
• 金额: $ 15.65万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1976
• 资助国家: 美国
• 起止时间: 1976-01-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3268551
• 关键词: Orthoptera; birefringences; cell cycle; cell type; chromosome movement; cinemicrography; computer simulation; electron microscopy; fluorescence microscopy; image enhancement; kinetosome; meiosis; micromanipulator; microtubules; mitotic spindle apparatus; nuclear membrane; phase contrast microscopy; tissue /cell culture

The goal is to understand the equal distribution of chromosomes to the daughter cells in mitosis and meiosis. An explanation for the normal success in chromosome distribution would also help explain the failures that result in Down's syndrome and other chromosome diseases in humans. Equal distribution depends upon directed chromosome movement in mitosis. The current explanation of movement in anaphase does not explain congression, the movement of chromosomes in prometaphase to a position midway between the spindle poles. An explanation of congression in terms of forces and mechanics is sought. The aim is not only to test current models, but to provide the basis for better models in the future. The plan is to characterize better what actually happens during congression. The forces that produce congression will be measured in absolute units. The possibility of pole-to-chromosome as well as poleward forces will be examined experimentally. Chromosomes in prometaphase commonly spend more time immobile and in contrary movement than in congression. The spindle conditions that underlie these vagaries of chromosome behavior will be characterized by studies of microtubules in living cells by image-enhanced polarization microscopy. Errors in microtubule arrangement that would lead to unequal chromosome distribution are common early in mitosis. The correction of errors by reorientation will be studied by observations of microtubules during reorientation in living and demembranated cells. The proper arrangement of microtubules is stabilized by tension forces. The minimal force required will be measured. The effect of force on microtubules will be determined by micromanipulation of microtubules in vitro. The possibility that tension stabilizes microtubule attachments to the spindle will be tested directly by imposing tension on unstable microtubules.

其目的是了解染色体的平均分布， 有丝分裂和减数分裂中的子细胞。 对正常现象的解释 染色体分布的成功也有助于解释 导致唐氏综合症和其他人类染色体疾病。 平均分布依赖于有丝分裂中染色体的定向运动。 目前对后期运动的解释并不能解释 联会，前中期染色体向某一位置的运动 在主轴两极的中间 用术语解释国会 力和力学的关系。 目的不仅是测试电流 模型，而是为未来更好的模型提供基础。 该计划 是更好地描述国会期间实际发生的事情。 的 产生国会的力将用绝对单位来测量。 的 极对染色体以及向极力的可能性将是 通过实验检验。 前中期的染色体通常花费更多 时间是静止的，并且在相反的运动中，而不是在国会中。 主轴 染色体行为的这些变幻莫测的基础条件将是 通过图像增强技术研究活细胞中的微管 偏光显微镜 微管排列错误导致染色体不均等 分布在有丝分裂早期是常见的。 通过以下方式纠正错误 重新取向将通过观察微管进行研究， 在活细胞和脱膜细胞中重新定向。 适当安排 微管的稳定性是由张力决定的。 最小力 所需的将被测量。 力对微管的影响将是 通过体外微管的显微操作测定。 的可能性 张力稳定微管与纺锤体的连接， 通过在不稳定的微管上施加张力来直接测试。