Determining the Tissue-Specific Importance of Centrosomes and the Spindle Assembly Checkpoint in Mitotic Fidelity (2015)

Undergraduate: John Cuningham

Faculty Advisor: Mark Peifer
Department: Biology

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During mitosis, cells must accurately segregate chromosomes to daughter cells. This is accomplished by the mitotic spindle, which is primarily formed by a pair of centrosomes. However, acentrosomal cells can still build spindles. We therefore used developing Drosophila wings and brains to investigate the importance of centrosomes in vivo. In wing epithelia, we found centrosomes are important for mitotic spindle assembly, chromosome segregation, spindle orientation, and cell viability. The Spindle Assembly Checkpoint (SAC), which monitors microtubule-kinetochore attachment, buffers acentrosomal wing cells, as loss of both centrosomes and the SAC leads to complete loss of wing epithelia. Interestingly, brain cells appear robust to centrosome loss, as no cell death was detected there. However, lack of centrosomes and the SAC dramatically perturbed brain development, including loss of neural stem cells. We are working to understand the basis for these phenotypes and the tissue-specific differences in the importance of centrosomes and the SAC.