Figure 3. Changing the level of Loaf in Dm8 does not affect R7 targeting.
(A–D) cryostat sections of adult heads stained for Chp (A’-D’, green in A-D), GFP (A’’, B’’, magenta in A, B), panR7-lacZ (red in C), HA (C’’, blue in C), or myrTomato (magenta in D). (A) wild type clones in which Dm8 is labeled with ortc2b-GAL4, UAS-CD8GFP; (B) loafΔ33 clones in which Dm8 is labeled with ortc2b-GAL4, UAS-CD8GFP. A’’ and B’’ show enlargements of labeled Dm8 dendrites. loaf mutant Dm8 dendrites and the R7 axons that target them have the normal position and morphology. (C) UAS-LoafHA; DIP-γ-GAL4, loafΔ33/loafΔ33; (D) tj-GAL4/UAS-LoafHA; loafΔ33/loafΔ33. The arrow in (D’) indicates minor R7 mistargeting that was not statistically significant. Scale bars, 20 μm (A–D), 5 μm (A’’, B’’). (E) quantification of the percentage of R7 axons that failed to reach the M6 layer in the indicated genotypes. n = 10 (loafΔ33/loafΔ20; DIP-γ -GAL4 rescue; tj-GAL4 rescue), or 5 (drf-GAL4 rescue). Error bars show mean ± SEM. ns, not significant by unpaired t-test. Expressing Loaf in Dm8 neurons in a loaf mutant does not cause R7 mistargeting. (F) diagrams explaining the predicted results if Loaf expression in R7 has to match its expression in Dm8. R7 and Dm8 both express Loaf (orange), which is also present in other cells in the brain. Removing loaf from Dm8 (gray) or expressing Loaf in Dm8 in a loaf mutant (gray in R7 and brain) would cause a mismatch and is predicted to result in R7 mistargeting. However, (A–E) show that there is no mistargeting in these situations (observed), indicating that Loaf does not act in Dm8 to regulate R7 targeting.
Figure 3—figure supplement 1. Changing Loaf levels in Dm8 has no effect.
