An acentriolar centrosome at the C. elegans ciliary base.

In animal cells, the functions of the microtubule cytoskeleton are coordinated by centriole-based centrosomes via γ-tubulin complexes embedded in the pericentriolar material or PCM. PCM assembly has been best studied in the context of mitosis, where centriolar SPD-2 recruits PLK-1, which in turn phosphorylates key scaffolding components like SPD-5 and CNN to promote expansion of the PCM polymer. To what extent these mechanisms apply to centrosomes in interphase or in differentiated cells remains unclear.