The accurate segregation of sister chromatids to daughter cells requires both the bipolar attachment of centromeres to the mitotic spindle and the correct positioning of the spindle with respect to the axis of cytokinesis. Cytokinesis always takes place perpendicularly to the axis of the spindle once chromosomes are segregated. These different events are coordinated in space and time in order to prevent the formation of aneuploid cells, a phenotype frequently observed in cancer and genetic diseases. The precise mechanisms leading to aneuploidy is unknown but is likely to be caused by either a defect in chromosome segregation, a defect in spindle positioning, a defect in cytokinesis or a combination of these defects. Although it is clearly established that faithful kinetochore/microtubule attachment is essential to prevent aneuploidy, several questions remain, such as:
What are the molecular mechanisms, which correct chromosome mis-attachment and how mis-attachment correction is coordinated with cytokinesis?
Using a multidisciplinary approach including genetic, video-microscopy and mathematical modeling techniques the aim of our lab is to identify the key players controlling chromosome segregation. We believe that our study performed in fission yeast will unveil new, basic and conserved mechanisms responsible for aneuploidy.