Finding treasures in frozen cells: new centriole intermediates

Centriole duplication has been an area of interest since the late 1800s when Boveri suggested that these structures were central organizers for mitosis and cell division. Two groups((1,2)) have delineated a linear pathway for centriole assembly. In C. elegans, Pelletier and coworkers((1)) have identified intermediates in the pathway using cryo-electron tomography. Surprising, the first intermediate is a hollow tube of 60 nm that increases in diameter and then elongates before acquiring microtubules. Similar structures have not been observed to date in other centrioles.