How Golgi grows

The formation of new Golgi has been unclear, but is thought to be by a process of either budding from the endoplasmic reticulum or autonomous replication from an existing Golgi structure. In 1 August Nature, Laurence Pelletier and colleagues at Yale University School of Medicine, Connecticut, US, show that in the protozoan parasite Toxoplasma gondii the Golgi replicates by lateral extension followed by medial fission (Nature 2002, 419:548-552).

Pelletier et al. used electron microscopy and video fluorescence microscopy to examine the development of the single Golgi in T. gondii during a whole cell cycle sequence. Serial thin sections indicated four distinct developmental stages; a single Golgi with a cross sectional diameter of 0.7µm, a twofold increase in diameter suggesting lateral cisternal growth, two Golgi side-by-side suggesting medial fission and finally, a single Golgi in each of the two nascent daughter cells.

To confirm these observations...