Figure 9.

Wnt Wg signaling not involved in critical period-sensitive OSN remodeling. A, Representative confocal images of Or42a OSNs innervating the VM7 olfactory glomerulus (Or42a-Gal4-driven UAS-mCD8::GFP) following critical period exposure (0–2 dpe) to vehicle only (oil, left) or 25% EB (right). Four genotypes are compared: (1) background control w¹¹¹⁸; UAS-mCD8::GFP/+; Or42a-Gal4/+ (control, top); (2) same genotype with a heterozygous wingless null (wg^I-17/+, second row); (3) same genotype with UAS-Drosophila frizzled-2 dominant negative (dFz2-DN, third row); or (4) the UAS-shaggy dominant negative (Sgg-DN, bottom). White arrows in EB control indicate OSN axonal membrane retraction punctae. Female brains were used for these experiments. B, Quantification of OSN innervation volume of the VM7 glomerulus for all eight conditions. Scatter plots represent all the data points and the mean ± SEM. Significance within genotypes from two-way ANOVA with Sidak's multiple-comparisons tests (bottom bars), or from multiple regression with two-tailed unpaired t tests to test interactions between genotype and treatment for Sgg-DN (dashed top bar), dFz2-DN (dashed second bar), and wg/+ (dashed third bar). Not significant (p > 0.05). **p < 0.01. ***p < 0.001.