Structure and proteomics on centrosome from differentiated and quiescent cells: the thymocyte case

We have applied cryo-tomography and proteomics analyses to centrosomes isolated from young lamb thymus– a convenient source of quiescent and differentiated cells. Those analyses have allow us to better depict the protein organization joining the two centrioles in such a cellular system, in the form of a disperse network of fibers and an amorphous density, both parts linked together. Protein composition of the centrosome have been compared with published data on centrosome extracted from cell culture , and presence of various protein reported implicated in the disengagement and dissociation processes questioned. C-NAP1, cohesin smc1 and furthermore condensin smc4 and ncapd2 have been localized on the amorphous density, however DNA hasn't. Subtomogram averaging processing have been applied to the centriolar wall, both on the proximal microtubule triplets and distal doublets; results have been compared to the already published structures of centriolar wall triplet from distant species basal bodies.