Fig. 5. In tea1+ cells, the formation of branches after TBZ-induced cell depolarization requires the presence of short microtubules but, in tea1 cells, formation of branches after TBZ treatment is independent of microtubule distribution. The frequency of cell branching was measured in G1 block-and-release experiments using cdc10-129 mutants that were either tea1+ (A,C,E) or tea1 (B,D,F). The genotype of each strain is indicated in each panel (A-F). In one set of experiments (A,B), cells were treated with either TBZ or MBC, or with TBZ plus MBC. In a second set (C,D), cells were treated with DMSO or TBZ, or with TBZ followed by wash-out of the drug after release from the G1 arrest. In a third set, a benzimidazole-resistant beta-tubulin mutant background (nda3-TB101) was used, and cells were treated with either DMSO or TBZ. The baseline frequency of branched cells is higher in tea1 mutants because they branch in response to the temperature shift required for the cdc10-129 arrest.