Biology Reference
In-Depth Information
6.4 The Loss of Asymmetry of Centrosomes Relates
to Centrosome Dysfunction and Tumorigenesis
As described above, the structural asymmetry between the two centrosomes is
important in many cellular processes during cell divisions. The intriguing questions
are, when cells contain extra centrosomes, whether this asymmetry is still main-
tained, and if not, how the extra centrosomes affect the cellular processes. Basto and
colleagues answered these questions through driving centriole overduplication in
fruit flies by overexpressing SAK, a protein kinase critical for initiating centriole
duplication (Basto et al.
2008
). Although the adult animals with SAK overexpression
are viable and fertile, their development is significantly delayed and the mitosis
period is longer. Cells with extra centrosomes initially form multipolar mitotic
spindles, but later on almost all multipolar spindles become bipolar by metaphase,
leading to normal partitioning of the chromosomes into two daughter cells. This
