In animal cells, microtubule assembly is usually initiated at one spec
ialized structure, the centrosome. By contrast in plant cells, microtu
bule assembly begins at a variety of locations within the cell. A memb
er of the tubulin gene family, gamma-tubulin, is localized to the cent
rosome in animal cells and is important in the assembly of microtubule
s in vivo. Recent reports have identified gamma-tubulin genes in plant
s and have described the complex intracellular distribution of the enc
oded polypeptides. Here, Harish Joshi and Barry Palevitz comment upon
how this information may help elucidate the organizing principles of t
he complex arrays of microtubules in plant cells.