Dicentracin gene expression levels in tissues of D. labrax. The dicentracin mRNA copy number was measured by real-time PCR in gills, skin, eyes, stomach and gut, and it was normalized as a ratio to 100 ng total RNA. Fish were sampled before stress (control), after 4 hours of confinement/crowding (stress), and then after 24 hours of recovery from stress. The means of five animals in each group are shown. Bars indicate standard error of the mean. Differences were determined by one-way ANOVA. Different letters indicate significantly different means (p < 0.05) between control, stressed and recovered fish groups.