GlgA-GFP indicates polar localization of glycogen in csrA mutant cells.
CsrA mutant cells harboring a plasmid encoding GlgA-GFP fusion protein were observed by time-lapse microscopy when growing in microfluidic devices. (A) shows a temporal montage of still images from different time points, starting with the emergence of a new individual (‘focal individual’) at time 10 min that produces three daughters and then stops dividing. GlgA-GFP signal accumulates at the old pole and eventually fills the whole cell. The focal individual is the last daughter of the cell at the bottom of the channel. (B) is a quantification of fluorescence intensity of the focal individual (‘mother cell’, yellow) and its young pole daughter cells (blue), for the focal individual’s first, second last, and last division. Fluorescence is extracted as integrated density. GlgA-GFP signal stays approximately the same in all daughter cells, but accumulates in mother cells with increasing pole age. Error bars denote standard error of the mean.