Figure 2.

Cell growth in agar pads is exponential. (A and B) Tracking single cells over several hours reveals exponential growth even holds for single cells in both wild-type (A) and frik (B). (Arrows) Elongation events that lead to filamentous cells in the frik mutant; (dashed lines) when growth arrests. (C) Both wild-type (black) and frik (cyan) have the longest cells in the exponential phase in liquid cultures with a steady decrease as cells transition into the stationary phase. (Straight lines through the various points are guides to the eyes.) (Inset) Representative growth curve from which the cell sizes were determined. (Gray area) What we call the “exponential” phase. (Anything outside of the gray area is considered the “stationary” phase.) (D) Frik continues to divide even after growth arrests in agar pads. Growth stops after 360 min in this example (indicated by the black outline around the picture). After this time, both a long cell and the shorter cells still divide to become shorter. (E) Frik tends to show budding off of two cells on opposite poles in short sequence. (Gray arrowhead) First septation event, followed by a second septation event (pointed out by the black arrowhead). To see this figure in color, go online.