Light-dependent transcriptional activity of CrebB in MB α/β neurons. A, Using UAS-FLP/hs-CrebB-B; CRE>mCherry::STOP>luc/R19B03 and UAS-FLP/+; CRE>mCherry::STOP>luc/R19B03 flies, we examined whether the induction of the CrebB repressor CrebB-B inhibits CrebB activity. N = 9–11 for each bar. In heat-shock treatment, males (3–4 d old) were kept at 32°C for 3 d. Luc activity was measured immediately after the heat-shock treatment. Error bars indicate SEM. Nonparametric ANOVA (Kruskal–Wallis test) followed by post hoc analysis using the Steel–Dwass test was performed for multiple pairwise comparisons. Bars with the same letter indicate values that are not significantly different (p > 0.05). B, The CrebB activity in MB α/β or γ neurons was measured in LD or DD using MB α/β-GAL4 (R41C10) or MB γ-GAL4 (R55D03). Samples were prepared between ZT 0 and ZT 2. N = 8–13 in each bar. Error bars indicate SEM. One-way ANOVA followed by post hoc analysis using Scheffe's test was used [one-way ANOVA, F(4,50) = 31.697, p < 0.0001; Scheffe's multiple comparisons: (1) vs (2), p < 0.0001; (1) vs (3), p = 0.0169; (1) vs (4), p < 0.0001; (1) vs (5), p < 0.0001; (2) vs (3), p < 0.0001; (2) vs (4), p = 0.9427; (2) vs (5), p = 0.5709; (3) vs (4), p = 0.0039; (3) vs (5), p = 0.0075; (4) vs (5), p = 0.9820]. Bars with the same letter indicate values that are not significantly different (p > 0.05). C, Memory on Day 5 in wild-type and Pdfr5304 flies. The Mann–Whitney U test was used for comparisons of CI. The permutation test with 10,000 random permutations was used for comparisons of MI. For MI, asterisks indicate a comparison between wild-type and Pdfr5340. **p < 0.01, ***p < 0.001. NS, not significant; N, sample size in each box. D, UAS-FLP/R61G12-LexA; CRE>mCherry::STOP>luc LexAop-TrpA1/R41C10 and UAS-FLP/R61G12-LexA; CRE>mCherry::STOP>luc /R41C10 flies were used. N = 5–6 for each bar. For activation of Pdf neurons by TrpA1, males (3–5 d old) were kept at 32°C for 2 d in DD. Error bars indicate SEM. Student's t test was used. **p < 0.01. E, F, The conditioning-dependent CrebB activity in MB α/β or γ neurons was measured immediately after 7 h conditioning (E) and on Day 1 (ZT 0–2) after 7 h conditioning (F). Student's t test was used. *p < 0.05, **p < 0.01. N = 6–9 in each bar. G, H, The conditioning-dependent CrebB activity in MB α/β was measured at ZT 0–2 (G) and ZT 16–18 (H) on Day 2 after 7 h conditioning. Student's t test was used. N = 9–10 in each bar. E–H, White bars indicate naïve males, and gray bars indicate conditioned males.