Pds1 depletion causes immediate spindle elongation in a phospho-mimetic Esp1 mutant.

<p>(<b>A</b>) Pds1 depletion causes synthetic sickness in <i>ESP1-3D</i> cells. Eight-fold serial dilutions of the indicated strains were spotted onto the indicated plates and grown at 25°C. (<b>B</b>) The <i>ESP1-3D</i> allele is semi-dominant in diploids. Ten-fold serial dilutions of the indicated diploids were grown in YEP + dextrose media, spotted onto the indicated plates and grown at 25°C. (<b>C</b>) The <i>ESP1-3D</i> allele is semi-dominant when complemented by a plasmid borne <i>ESP1 (ESP1-CEN-HIS3)</i>. Ten-fold serial dilutions of the indicated strains were grown in media lacking histidine, spotted onto the indicated plates and grown at 25°C. (<b>D</b>) Mitotic spindle morphology of individual <i>ESP1-3D</i> cells depleted of Pds1. <i>PDS1-AID SPC42-eGFP</i> and <i>ESP1-3D PDS1-AID SPC42-eGFP</i> cells were grown at 25°C to log phase and arrested in G1 with α-factor. 30 min before α-factor release +/- auxin was added. Cells were released at t = 0 and at t = 25 min cells were plated onto YPD live microscopy pads +/- auxin and Spc42-eGFP was imaged every minute. Each strain was imaged at least two times in each condition. Cells that undergo <i>normal metaphase spindle formation</i> are shown in black. Cells that undergo <i>immediate spindle elongation</i> upon spindle formation are shown in green. Cells that exhibit <i>failed or no anaphase</i> spindle elongation are shown in red. See <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007029#pgen.1007029.s005" target="_blank">S3 Fig</a> for cell traces of experiments done in the absence of auxin and <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007029#pgen.1007029.g003" target="_blank">Fig 3</a> for tabulation of all imaging data. The scoring metric is described in the text and in the material and methods.</p>