SPB building blocks

For many years, John Kilmartin and colleagues have painstakingly tracked, using electron microscopy (EM), the duplication of the SPB, which is budding yeast's version of the centrosome. The painstaking part comes in because only a few sections happen to catch the tiny SPB in the act. The SPB has a protrusion called the half bridge. At some point this half bridge doubles in size. Another SPB accumulates on the far end of this structure, then the two SPBs split apart. Before the splitting occurs, the far ends of the two half bridges are too close to...