Figure 3: Exposure I: Changes in mRNA levels of steroidogenic enzymes. Gene expression of star (a), cyp11a1 (b), hsd3b1 (c) and cyp19a1b (d) in 20dpfZF exposed to concentrations of EE2 for five days (from 20 to 25 dpf). Box plots represent median (—), 25th and 75th percentiles (lower and upper end of boxes), minimum and maximum values (end of the whiskers) for polled whole-body homogenates (n=3 pools of at least 20 fish each). Target genes were normalized to geometric mean of two reference genes (β-actin, ef1a). Nominal exposure concentrations include 0, 5, 25 and 50 ng EE2L-1. Means with different letters are significantly different (P< 0.05) as determined by Oneway ANOVA followed by Tukey’s HSD post hoc test.