Figure 1.

Effects of mid1 overexpression. (A) Effect on cell growth. Wild-type cells overexpressing mid1p or HA-tagged mid1p were streaked on EMM plates without thiamine and grown at 30°C for 4 days. (B) Effects on cell morphology and septum formation. Cells overexpressing mid1p (pREP41X-mid1) were grown at 30°C for 24 h and 32 h after thiamine removal from the medium and were stained with calcofluor. Note formation of bulges at the cell center, increased calcofluor staining in the bulge region (arrow) and abnormal placement of septa. Bar: 10 μm. (C) Quantitative analysis. Effects of mid1 overexpression from pREP41X on growth rate (top), bulge formation (middle), and on septum position (bottom) were assayed from 16 h to 26 h after thiamine removal of the medium. Growth rate was determined by cell count with an hemacytometer. For growth rate and bulge formation, mean (± SEM) from two independent experiments are presented. For septum position, 100 cells or more were scored at each time point.