Unraveling the molecular details of centriole elongation.

Centrosomes are the major microtubule-organizing centers in most metazoan cells. At their core sit cylindrical centrioles composed of nine radially symmetrical microtubules blades and an evolutionarily conserved assemblage of unique proteins. Length of the centriole barrel varies across species, in different cell-types within the same animal, and between centrioles in the same cell. Furthermore, defects that alter centriole length can lead to chromosomal instability, tumorigenesis, infertility, and ciliopathies. In this review, we summarize our current understanding of how centrioles elongate, the molecular components involved, and their functional interplay.