Fig. 1

Microfluidics setup. a Caulobacter crescentus divides asymmetrically into a surface attached stalked cell (which we call mother) and a motile swarmer cell (which we call daughter). The figure shows five stages of a cell division cycle of a stalked cell (the duration of the cell cycle of a stalked cell is about 60 min). b Experiments were conducted using microfluidic chips with eight parallel channels. Environmental conditions were controlled by flowing medium through the channels (tubing shown for one channel). Stalked cells attached to the glass surface at the inside of the chip. Upon division, and for the C. crescentus strain used in this study, about one third of C. crescentus swarmer cells attached downstream of the stalked cell and were observable, while the other swarmer cells were washed out. c C. crescentus cells were monitored with time-lapse microscopy during growth under controlled conditions. Images were acquired every 5 min. The stalked mother cells divided asymmetrically about once an hour into stalked mother and motile daughter cells. Three successive images (minute 0, 5, 10) of two cell lineages (blue and red) are shown. Flow direction is from left to right. The blue cell divided between Frame 1 and Frame 2, the red cell divided between Frame 2 and Frame 3. The pre-divisional mother cells (blue cell: Frame 1. red cell: Frame 1–2) consists of the stalked mother cell (labeled 1) and swarmer daughter cell (labeled 2). Once cell division has completed, the stalked mother cell was marked 3 and the motile daughter cell was marked 4. When the blue cell divided, the swarmer daughter cell was washed out and was not observable anymore. The swarmer daughter cell that attached and remained in the channel differentiated into a stalked cell and initiated cell division (labeled 4). Figure a and b were reproduced from [17], and produced by Stefanie Stutz (http://stephaniestutz.ch/)