Fig. 1. Time course for ß-naphthoflavone (BNF)-induced CYP1A mRNA measured by Q-RT-PCR. Juvenile lake trout were randomly assigned to treatment groups (N=8 for each treatment group) and given an intraperitoneal injection of BNF in corn oil (50 mg kg^–1 body mass) or corn oil alone. Whole brain tissue was taken at 10 different time periods between time zero and 32 days. Total RNA was extracted and analyzed for CYP1A mRNA levels using Q-RT-PCR. Data were analyzed using a two-way analysis of variance followed by a Tukey–Kramer adjustment for all pairwise comparisons. At most time periods, significantly higher levels of CYP1A expression were found in each induced group over its respective control group (designated by *; Tukey–Kramer, P<0.0001).