New Laser Microbeam Experiments on Forces that Move Chromosomes

在有丝分裂后期分离染色体所需的力量是这项提议的焦点。这项工作的一个阶段将确定星体力量是否拉动担子菌、硅藻和哺乳动物(PTK)细胞的纺锤体极。这些力量将通过使用激光微束在后期切断中心纺锤体来表现出来。在工作的另一阶段，将使用红外激光诱导的光学力陷阱来相对定量地测量子囊菌在后期A和B期间的作用力。将估计主轴和主轴在主轴总伸长力中的相对贡献。这项工作将直指有丝分裂过程中作用在染色体上的力的位置问题的核心。此外，光学力陷阱作为研究细胞内运动性的分析工具的发展将引起整个细胞生物界的兴趣。

The forces required to separate chromosomes at mitotic anaphase are at the focus of this proposal. One phase of the work will determine whether or not astral forces are pulling on the spindle poles in a Basidiomycete, a diatom and mammalian (PtK) cells. These forces, will be made manifest by severing the central spindle at anaphase using a laser microbeam. In the other phase of the work, infrared laser-induced optical force traps will be used to make relative-quantitative measurements of forces operating during anaphase A and B in an Ascomycete. Relative contributions of asters and spindles to the total spindle elongation force will be estimated. The work will go right to the heart of the question about location of forces acting on chromosomes during their movement at mitosis. Furthermore, the development of optical force traps as an analytical tool for studying intracellular motility will be of interest to the entire cell biology community.