Description:

My laboratory maintains cultures of immortalized Drosophila cells for studying cell division and related motility. Cell cultures of Drosophila Kc cells are subjected to double stranded RNA interference to suppress the expression of specific proteins such as centrosomin. Cells that lack centrosomin lack mitotic centrosomes which are usually located at the spindle poles. Live Kc cells dividing under those conditions are non- invasively observed using a high resolution polarized light microscope that is being developed in the ADLC Program.

Progress:

We have found that in cells lacking mitotic centrosomes the structure and dynamics of the mitotic spindle is changed surprisingly little compared to control cells. In late Anaphase, however, RNAi treated cells show birefringent fibers between segregated chromosomes that frequently spread to the cell surface and fail to build a spindle midzone, often leading to the failure of cell division. Our results indicate that the cell has several different pathways for building and maintaining a mitotic spindle and that centrosomin is involved in building the spindle midzone and thus plays a critical role in the success and failure of the complex and fateful event of cell division.