Fig. 4. Re-initiation of tip growth converts tip-associated SICS dots into rings around the cortex. (A,B) cdc10.v50 cells were grown to early-log phase in YES media and cell-cycle progression was arrested by incubation at 36°C for 3.5 hours before the imposition of osmotic stress by the addition of sorbitol to a final concentration of 1.2 M. (A) Samples were taken at the indicated time points; arrows indicate rings of SICS staining around the cell cortex. (B) Quantification of the appearance of SICS at cell tips and SICS within the cell in sorbitol-treated, G1-arrested cdc10.v50 cells and in an asynchronous population of wild-type cells growing at 36°C. (C-E) Wild-type cells grown to mid-log phase in YES media at 30°C were stained in fluorescent lectin before being returned to culture. Continued growth resulted in dark non-stained tips. (C) Wild-type cells showing lectin, Calcofluor (calc.) or both (merge: Calcofluor in red, lectin in green) stainings at the indicated times post-stress. (D) Quantitation of the kinetics with which cells with dark tip regions appeared in the cultures following the addition of an equal volume of either pre-warmed YES media (control) or YES media containing 2.4 M sorbitol (sorbitol). (E) Quantitation of the kinetics of the appearance of dark tip-growth regions in lectin-treated wild-type cells following the addition of an equal volume of either pre-warmed YES media containing 1.2 M KCl (KCl) or 2.4 M sorbitol (sorbitol). Scale bars: 5 µm.