Figure 1.

Crb controls ROS production through the inhibition of Rac1 and NADPH oxidase in epithelial tissues. (A) Monitoring of ROS production using lucigenin assay in wild-type embryos, Crb overexpressing embryos (Crb Over.), crb^11A22 mutant embryos (null allele), Rac1^V12-expressing embryos, and in embryos expressing Rac1^V12 and overexpressing Sod1 (Sod1 over.). Error bars represent the 95% confidence level. (B) crb homozygous mutant clones were produced in adult crb/+ female flies (mutant clones are GFP negative). Ovaries were then dissected, incubated in the presence of the ROS-sensing DHE probe, and mounted for confocal microscopy analysis. (C) Crb was clonally overexpressed in the follicular epithelium, and ROS production was assessed using DHE and confocal microscopy. Crb overexpressing clones are positively marked with GFP. (D) Determination of ROS levels using DHE in crb mutant clones in which Rac1 was knocked down. (E and F) After induction of crb homozygous mutant clones in crb/+ female flies (mutant clones are GFP-negative), ovaries were incubated in the presence of the Rac1 activation inhibitor NSC23766 (E) or the NADPH oxidase complex inhibitor apocynin (F). Then, ROS levels were determined using DHE and confocal microscopy. Bar, 10 µm.