QPCR showing expression of STAT1 and Mx mRNA in IFN-stimulated adherent head kidney leukocytes. The cells were stimulated with 10 U/mL of recombinant Atlantic salmon IFN-a1 or 200 ng/mL of recombinant rainbow trout IFNγ. The mRNA levels were normalized against EF1AB. (A) STAT1 mRNA expression after 4, 12 and 24 h of stimulation. (B) Mx mRNA expression after 4, 12 and 24 h of stimulation. The results are an average of samples from three fish and presented as fold increase relative to unstimulated head kidney cells. Experiments were performed twice with reproducible results. Error bars show standard deviation.