The developing Drosophila eye: an oncoming model to study centriole reduction

Abstract

In the developing Drosophila eye the centrioles of the differentiating retinal cells are not surrounded by the microtubule nucleating γ-tubulin suggesting that they are unable to organize functional microtubule organizing centers. Consistent with this idea Cnn and Spd-2, involved in γ-tubulin recruitment, and the scaffold protein Plp that plays a role in the organization of the pericentriolar material are lost in the third larval stage. However, the centrioles maintain their structural integrity and both the parents accumulate Asl and Ana1. Although the loading of Asl points to the acquisition of the motherhood condition, the daughter centrioles failed to recruit Plk4 and do not duplicate. However, it is surprising that also the mother centrioles that accumulate Plk4 never duplicate. This suggests that the loading of Plk4 is not sufficient, in this system, to allow centriole duplication. By half of the pupal life the centriole number decreases and structural defects, ranging from incomplete or lacking B-tubules, are detected. Asl, Ana1 and Sas-4 are still present, suggesting that the centriole integrity does not depend on these proteins.