Abstract
The separation of replicated chromosomes is an essential part of the cell division. In general, the mode of chromosomal movement was categorized to two phases. The first phase is the poleward movement of the chromosomes (anaphase A) and the second one is the movement by the separation of the spindle poles (anaphase B). However, the process of anaphase B in plant cells has been unclear because they have an acentrosomal spindle and no conspicuous spindle elongation has been reported. In this study, we visualized microtubules and cell nuclei in transgenic tobacco BY-2 cells using GFP-tubulin and histone-RFP. Time-sequential images of the spindle growth and chromosomal separation and quantification of the dynamics by image processing, we found a clear process of anaphase B in tobacco BY-2 cells after the start of anaphase A. Interestingly, anaphase A and B were overlapped following the initiation of anaphase A.
