Ault J G, Rieder C L
Wadsworth Center for Laboratories and Research, Albany, New York 12201-0509.
Curr Opin Cell Biol. 1994 Feb;6(1):41-9. doi: 10.1016/0955-0674(94)90114-7.
During the past year important progress has been made in refining our understanding of how chromosomes become equally distributed to daughter cells during mitosis. Unlike the situation in diatoms and yeast, it now appears that spindle pole (centrosome) separation during spindle formation and anaphase B is mediated in vertebrates primarily by an astral pulling, and not a pushing, mechanism. Kinetochore motility is directionally unstable, which has important consequences for how chromosomes move to the equator of the forming spindle. Finally, the observation that sister chromatid disjunction occurs even in the presence of high levels of maturation promoting factor reveals that the series of biochemical events responsible for this phenomenon is not an obligatory part of the pathway by which the cell exits mitosis.
在过去的一年里，我们在深化对有丝分裂过程中染色体如何均等分配到子细胞的理解方面取得了重要进展。与硅藻和酵母的情况不同，现在看来，在脊椎动物中，纺锤体形成和后期B阶段的纺锤极（中心体）分离主要是由星射线牵拉机制介导的，而不是推动机制。动粒运动在方向上不稳定，这对染色体如何移动到正在形成的纺锤体赤道面具有重要影响。最后，即使在存在高水平成熟促进因子的情况下姐妹染色单体仍会分离这一观察结果表明，导致这一现象的一系列生化事件并非细胞退出有丝分裂途径的必然组成部分。
