Fig. 5. nvd-Dm RNAi animals show reduced ecdysteroid titer. Larvae were collected 30-42 hours after egg laying (AEL), corresponding to the first instar larval stages. Ecdysteroid titers of control (black box) and the nvd-Dm RNAi animals (shaded box) on food with or without 7-dehydrocholesterol (7dC) were determined by radioimmunoassay. The results are depicted as picograms (pg) of 20-hydroxyecdysone equivalents/mg initial body weight on the vertical axis. Each bar represents the mean±s.e.m. from multiple independent samples. The following number of independent samples was examined: four (control), five (RNAi) and six (control + 7dC and RNAi + 7dC). ^*P<0.01 by Student's t-test.