FIG 5.

Hyperelongated cells are preferentially vulnerable to mild shear forces. (A) NS2::riboswitch::Cdv3-mTurq strains were analyzed by flow cytometry 0, 24, or 48 h after induction with 800 μM theophylline. Increased forward scatter and chlorophyll-associated red autofluorescence were observed, and these changes were correlated with the increased cell size of Cdv3-overexpressing cells. Cell counts are gated into wild-type length (blue box) and elongated (red box). (B) Uninduced (top) and Cdv3-overexpressing (bottom) cyanobacterial cultures were exposed to increasing pressure and lytic forces on a cell disruptor, and the population was monitored by flow cytometry. The proportions of elongated cells (red) relative to WT lengths (blue) are represented in pie charts for each condition. (C) Quantification of the proportions of intact cells remaining after cell disruption with increasing pressures. P values from two-tailed unequal variances t tests against the equivalent uninduced control are reported above the relevant bars wherever P < 0.05. (D) Quantification as in panel C, but where only the proportions of elongated cells are tracked.