Figure 8.

Correlation between the extent of polar growth and regions of absent cER. (A) Length/width ratio of daughter cells of WT and selected double-deletion strains (200 < n < 206; error bars show SEM; the value for the WT is taken from Fig. 2 D). ***, P < 0.001. (B) Quantification of gaps of ER staining below the bud tip in 1–2 µm buds of WT and selected single- and double-deletion strains expressing HMG1-GFP as marker for the cER. Shown are the means of 40 < n < 149 cells derived from at least two independent strains with a deviation of <8%. (C) The percentages of cells displaying no ER below the bud tip were plotted against their length/width ratios. Values were taken from A and B, respectively. Strains carrying either a deletion of EPO1, SCS2, or both are indicated by the black symbols. The regression line shows the linear correlation between both values in these strains (R² = 0.92). Blue dots present the values of the WT strain and strains where the connections between cER and bud tip are impaired to an unknown extent. (D) Model of cER anchorage at the cell tip. The top half depicts WT, and the bottom half shows Δepo1 cells. The blue line indicates a newly incorporated cell wall and PM material.