ANALYSIS AND CONTROL OF CHROMOSOME MOVEMENT

我们的目标是理解染色体的平均分布到 有丝分裂和减数分裂中的子细胞。对常态的一种解释 染色体分布的成功也有助于解释失败的原因 这会导致唐氏综合症和其他人类染色体疾病。 在有丝分裂中，均匀分布依赖于定向的染色体运动。 目前对后期运动的解释不能解释 前中期染色体向某一位置的运动。 在主轴两极之间的中间。“会议”的术语释义 力和力学的关系。其目的不仅仅是测试电流 模型，但为未来更好的模型提供基础。这个计划 是为了更好地刻画会议期间实际发生的事情。这个 产生压差的力量将以绝对单位来衡量。这个 极到染色体以及极向力的可能性将是 经过实验检验。处于前中期的染色体通常花费更多 时间是静止的，处于相反的运动中，而不是在运动中。主轴 这些变幻莫测的染色体行为背后的条件将是 以图像增强研究活细胞中的微管为特征的 偏振显微镜。 微管排列错误会导致染色体不等长 在有丝分裂的早期，分布是常见的。通过以下方式纠正错误 重新定向将通过观察微管在 活细胞和去膜细胞的重新定位。恰当的安排 微管的长度由张力力稳定。最小作用力 所需的数据将被测量。力对微管的影响将是 通过体外对微管的显微操作来确定。这种可能性 这种张力稳定的微管连接到纺锤体上将是 通过对不稳定的微管施加张力直接进行测试。

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.