Birth control for centrioles

Omnis centriolus e centriolo—every centriole comes from a centriole. This statement underlies the standard model of centrosome duplication, in which daughter centrioles that will form the foundation of a new centrosome must be patterned on some kind of template provided by a mother centriole. On page 1171, Khodjakov et al. now demonstrate that vertebrate cells are fully capable of assembling centrioles de novo, overturning this long-held belief and suggesting a different function for the mother centrioles.

A few specialized cell types, such as clam zygotes and rabbit blastomeres, previously have been shown to form centrioles de novo, but these examples were thought to be exceptions. The new work argues otherwise. The authors arrested CHO cells in S phase, and then destroyed their centrosomes with a laser. In this system, a loose cloud of pericentriolar material (PCM) forms, and within...