Fig. 5.
Expression of Crb_C in pupal and adult wild-type and mutant flies. (A-F′) Confocal images of representative optical sections from retinal whole mounts of adult (1 day old female flies; A-D′) and pupae (72 h APF; E-F′) from w* and crb p13A9 animals, stained for Crb. (A-D) α-Crb_Cq4 detects all isoforms, α-Crb_B/D is specific for Crb_B/D and α-Crb_C is specific for Crb_C. Arrows indicate stalk membrane of PRCs. Dashed white boxes in C′ and F indicate ommatidial clusters with no obvious α-Crb_C immunoreactivity at stalk membranes. Scale bar: 5 μm. (G) Western blot of protein extracts isolated from control (w*) and crbp13A9 homozygous mutant adult heads (2 days old female flies), probed with α-Crb2.8, detecting all isoforms. The upper arrow points to a slower migrating protein present in head extracts of wild-type flies, which is missing in the mutant (*). The lower arrow points to a protein that is detected in w* and crbp13A9, which co-migrates with overexpressed Crb_A (data not shown). The identity of the other bands cannot unambiguously be determined. (H) Graph depicts fold-change (on y-axis, quantified as Δ ΔCt) after normalisation with housekeeping gene Gapdh1, for different crb transcripts (on x-axis) from heads between 72 h APF (pupal stages) and newly eclosed adult. Whilst there is negligible change in crb-RA (fold-change=0.99) and crb-RB/D transcripts (fold-change=0.98), crb-RC transcript levels increase by 5.39-fold between the last day of pupal development and at eclosion (72 h APF and adulthood). Error bars depict s.e.m.