Figure 4.

Expression of a dominant-negative CSN5 transgene in larval LNs blocks normal TIM degradation. A–D, The dominant-negative UAS-CSN5^DN2 transgene was expressed via Pdf_0.5-Gal4 (Pdf > CSN5^DN2) and TIM degradation measured as in Figure 2 with light pulses starting at ZT15 (A, B) and ZT23 (C, D). TIM levels (red) in LNs of Pdf > CSN5^DN2 larvae were compared with control y w and UAS-CSN5^DN2 larvae (two left panels) and CSN5^null mutant larvae (right panels). The images on the left are representative of at least five brains stained per time point in at least four independent experiments. Quantitation was performed for three of these experiments using at least five brains per genotype, except the UAS-CSN5^DN2 control which had at least three brains per experiment. Error bars show SEM. The quantitation reveals that levels of TIM degradation are similar in Pdf > CSN5^DN2 and CSN5^null larvae (p > 0.1). Levels of TIM degradation are significantly less in Pdf > CSN5^DN2 and CSN5^null larvae than in y w larvae (p < 0.001).