Figure 4.

Doubling Myo2p cellular levels suppresses cytokinesis defects in myp2Δ and cdc8-27 cells. (A–C) The influence an extra copy of myo2 imparts on the temperature-sensitive phenotype of a myp2Δ strain was assessed by comparing cell morphology and contractile ring integrity (A), growth (B), and cytokinesis defects (C) in myp2Δ YFP-myo2 versus myp2Δ 2xYFP-myo2 strains. (A) Cells grown at 25 and 36°C were imaged and processed in identical manner using DIC (left) and YFP (right) filters by light microscopy. Bar, 4 μm. (B) Cells were grown at 25 and 36°C on YE5S plates containing phloxin B, which labels dead cells (dark pink) over live cells (light pink). (C) Cells grown in YE5S media at 25 and 36°C were treated with Hoechst stain to mark nuclei and cytokinesis phenotypes scored as described in Figure 1A. (D–F) As in A–C, only the temperature-sensitive cdc8-27 mutation was used in place of the myp2Δ mutation. Phenotypes were compared after growth at 25 versus 32°C. Bar, 4 μm.