Pvr, Ras1 and the MAPK pathway control cell size in a Drosophila hemocyte-like cell line. (a) Schematic of canonical Ras/MAPK signaling. (b) Control and RNAi-treated S2R+ cells fixed and stained for microtubules (20× magnification). Pvr and Ras1 RNAi cause a decrease in cell area, whereas Gap1 RNAi causes an increase in cell area compared to control. (c-e) Charts of the mean percentage change in volume of RNAi treated or Pvf transfected S2R+ cells relative to control cells, as measured using a CASY counter. (c) Silencing of positive regulators of the Ras/MAPK pathway causes a reduction in cell diameter, whereas silencing of Gap1, a negative regulator of Ras1 signaling, causes an increase in cell diameter. (d) Silencing of Pvf1, 2 or 3 individually has no effect on cell volume, but silencing of Pvf2 and Pvf3 in combination significantly reduces cell size. (e) Over-expression of Pvf2 or Pvf3, but not Pvf1 leads to an increase in cell volume. This affect is dependent on Pvr. Error bars indicate the standard error of the mean.
Sims et al. Genome Biology 2009 10:R20 doi:10.1186/gb-2009-10-2-r20