Microscopy analysis of mother-specific promoter expression.

<p>(A) Time-lapse fluorescence microscopy of the <i>TXC</i> promoter (Y02569-GPY022) and <i>TXC2</i> promoter (Y02569-GPY020) strains. Cells were grown in synthetic complete glucose media and induced with 200 ng/μl ATc for 10 h. Selected frames at 60 min intervals are shown starting 60 min after induction. Each frame is a combination of the brightfield and green fluorescence channels captured using a 60x objective. White lines represent scale bars with a length of 10 μm. (B) Time-lapse frame analysis for the <i>TXC</i> promoter strain for all cells that become mothers during the 10 h experiment. Frames representing the time when cells reach the S phase and a bud appears are designated by purple shaded boxes. The heat maps are generated based on the average fluorescence values for cells taken by ImageJ analysis and corrected for background fluorescence. Each column represents fluorescence values of one cell for each of the 60 frames taken during the 10 h span and is formatted independently of the others. Minimum fluorescence values are colored as white, maximum as green. Cells are aligned based on the order when their first daughter bud appears. Column 10 shaded in pink represents a cell that despite becoming a mother cell never fluoresces significantly above background levels. For the <i>TXC</i> strain, cells are numbered based on the order they become fully grown. Cells No 8 and No 15 are omitted from the frame analysis since they appear to arrest during the 10 hours span of the experiment thus not becoming mothers.