Figure 1.

Localization of MTOCs in A. gossypii. (A) Images of a tip compartment expressing AgTUB4-YFP to localize MTOCs and stained with Hoechst to visualize nuclei. (B) Images of a hyphal compartment with a calcofluor stained septum and YFP-marked MTOCs. No YFP fluorescence can be seen at the septum. (C) Images of A. gossypii hyphae before and after incubation with 15 μg/ml nocodazole for 1 h and at different times after washout of the drug. Nuclei are stained with Hoechst and microtubules are labeled with anti-α-tubulin antibodies. The untreated hypha shows cMTs, one metaphase spindle before orientation along the growth axis and fluorescent foci representing SPBs. After nocodazole treatment only SPB foci are detectable with anti-α-tubulin antibodies. Twenty minutes after nocodazole washout, faintly stained short cMTs reemerged at the nuclear SPBs (arrows). By 30 min, the microtubules seemed similar to untreated cells. Bars, 5 μm (A–C).