Figure 8.

Model of MT and RanGAP band formation during PPB development. Black lines, red circles, green dots, and arrowheads show plasma membrane, MTs, RanGAP, and the center of the PPB, respectively. (A) Broad MT band forming stage. Many interphase cells and some mid-prophase cells have broad MT band and RanGAP proteins are widely diffused in the cytoplasm. (B) CDZ-forming stage. Most of mid-prophase cells and some late prophase cells have narrow MT band (less than 7 µm wide) and RanGAPs start to gather around the PPB region, but they are located slightly toward the inner cytoplasmic side from the MT band. (C) Established CDZ. A packed-narrow MT band (2–5 µm wide) and RanGAPs are concentrated into the MT band and form a CDZ in a certain time of late prophase. The plasma membrane in the CDZ is colored orange.