Fig. 2. IAA uncouples bud formation from nuclear division in haploid cells. Exponentially growing haploid 1287h cells were added to YEPD containing 0.5% IAA and incubated for 24 hours. (A) Cells stained with DAPI. (B) DIC images of the cells shown in A. Open arrow, wide filaments; solid arrow, narrow filaments; solid arrows with barbed tails, filaments with a mixture of wide and narrow compartments. (C) Cells were treated as above for 8 hours and Cdc11 visualised by immunocytofluorescence using an anti-Cdc11 antibody as described previously (Sudbery, 2001). (D) The same cells as in C, stained with DAPI. Septin rings form in the absence of nuclear division. (E) Cells were grown for 16 hours in YEPD plus 0.5% IAA, treated with zymolyase and stained with DAPI. Cells that contain nuclei separate after the zymolyase treatment. Scale bars: 10 µm (A,B,E); 5 µm (C,D).