This chapter reviews the centriole and associated structures. The main part of the centriole and basal body is the centriolar cylinder, the radially symmetric structure consisting of nine interconnected triplets of microtubules (MTs). The centriolar cylinder is not an equivalent of the centriole or the basal body, because the latter two organelles may contain some other important structures (sattelites, connectives, etc.) The centrosome can organize MTs in four different patterns: as a mitotic spindle, as an interphase network, as axonemes (ciliary or flagellar), or as a new centriole (basal body). Centriole and basal body formation is composed of three stages: foundation of the axial structure and MT triplets on it; elongation of the triplets and formation of a centriolar cylinder; and final restructuring of the centriolar cylinder, corresponding to the functional maturation of the organelle. Centriolar maturation consists of some structural changes. First, the cartwheel in the proximal part of the cylinder disappears and the amorphous hub appears in the distal part. Second, connectives between the inner MTs of the triplets are formed. Third, appendages appear at the distal end of the centriole. And finally, the mature centriole is surrounded by MTNCs—that is, pericentriolar satellites, mitotic halo, and free microtubular convergence foci.
ASJC Scopus subject areas
- Cell Biology