Basal body timing

Aggregation of γ-tubulin, pericentrin, and myosin II (GPM) precedes de novo basal body assembly, according to a report from Kim et al. on page 719. The number of basal bodies formed is controlled by the duration of γ-tubulin phosphorylation.

Until now, it has not been clear whether basal body and centriole formation occurred before or after clouds of pericentriolar material take shape. To answer that question, the researchers turned to Naegleria gruberi, which start life with amoeboid shapes but differentiate into swimming flagellates when food becomes scarce. During differentiation, the cells assemble basal bodies de novo, providing scientists with a window into the process.

The researchers knew that after the cells are transferred to a dilute buffer, γ-tubulin and pericentrin concentrate together in the cell. The percentage of cells with a concentrated region of...