Positioning of medial actin rings affected by eccentrically located nuclei in a fission yeast mutant having large vacuoles.
In Schizosaccharomyces pombe wild-type cells, the nucleus positions in the middle of the cell where the cortical actin ring is assembled prior to septum formation. ste12 mutants contain a few large vacuoles. In a considerable fraction of ste12 cells, the nuclei and septa were eccentrically positioned. Both extension of spindle microtubules in the anaphase and post-mitotic migration of sister nuclei to the cell poles were partially disrupted, probably due to enlarged vacuoles. In spite of the eccentric positioning of nuclei, the cortical actin ring overlays the displaced pre-mitotic nucleus. This observation supports the notion that the nucleus dictates the division site in fission yeast.
Morishita M, Shimoda C