Fig. 5. Compromised structure and function of microtubules in the wat1 mutant. (A) Impaired microtubules. Wild-type (left) or wat1-deleted cells were grown at 26°C (middle) and shifted to 36°C for 2 hours (right). Cells were fixed and processed for immunofluorescence microscopy using anti--tubulin antibody. Images from a confocal microscope are shown. Note that wat1-deleted cells are bigger than wild type because they are diploid. (B) Unequal chromosome separation with microtubule defects. wat1-deleted cells grown at 26°C (upper) and 36°C (for 2 hours, lower) were processed for immunofluorescence microscopy as in A and observed under a conventional microscope after staining with DAPI. Anti-tubulin staining (left), DAPI (middle) and merged images (right) are shown. (C) Hypersensitivity to thiabendazole (TBZ). Cells of wild type, wat1-5235, wat1-deleted, TBZ-resistant nda3-ben1 (Yamamoto, 1980) and TBZ-supersensitive atb2 mutants (Adachi et al., 1986) were spotted onto rich plates in the absence (-TBZ, left) or presence of thiabendazole (+TBZ, 20 µg/ml, right) as serial dilutions (10⁶ cells in the left row and then diluted 10-fold in each subsequent spot rightward) and incubated at 26°C for 3 days. Scale bars: 10 µm in A,B.