Oscillatory movements of monooriented chromosomes and their position relative to the spindle pole result from the ejection properties of the aster and half-spindle.

作者：C L Rieder, Edwin A. Davison, Lawrence C. W. Jensen, Lynne Cassimeris, E. D. Salmon · 发表于：The Journal of Cell Biology · 年份：1986 · DOI：10.1083/jcb.103.2.581 · 被引用次数：313 · 研究领域：Microtubule and mitosis dynamics、Genomics and Chromatin Dynamics、DNA Repair Mechanisms

During mitosis a monooriented chromosome oscillates toward and away from its associated spindle pole and may be positioned many micrometers from the pole at the time of anaphase. We tested the hypothesis of Pickett-Heaps et al. (Pickett-Heaps, J. D., D. H. Tippit, and K. R. Porter, 1982, Cell, 29:729-744) that this behavior is generated by the sister kinetochores of a chromosome interacting with, and moving in opposite direction along, the same set of polar microtubules. When the sister chromatids of a monooriented chromosome split at the onset of anaphase in newt lung cells, the proximal chromatid remains stationary or moves closer to the pole, with the kinetochore leading. During this time the distal chromatid moves a variable distance radially away from the pole, with one or both chromatid arms leading. Subsequent electron microscopy of these cells revealed that the kinetochore on the distal chromatid is free of microtubules. These results suggest that the distal kinetochore is not involved in the positioning of a monooriented chromosome relative to the spindle pole or in its oscillatory movements. To test this conclusion we used laser microsurgery to create monooriented chromosomes containing one kinetochore. Correlative light and electron microscopy revealed that chromosomes containing one kinetochore continue to undergo normal oscillations. Additional observations on normal and laser-irradiated monooriented chromosomes indicated that the chromosome does not change shape...