qRT-PCR analysis of six genes in gills of six smoltifying Atlantic salmon. The same data as in Figure 1, but now normalized against an index of the three best genes (β-actin, EF1AA and EF1AB) calculated with the geNorm software. The four groups were analyzed with Kruskal-Wallis test, and if significant, the overall p-value is given in the graphs. For β-actin, there were significant differences between the presmolt and the smoltified group (p < 0.05), the presmolt and the desmolt groups (n<0.01) and between the smolt and desmolt groups (p < 0.05). For EF1AA, there was a significant difference between the presmolt and the desmolt groups (p < 0.01). For EF1AB, there was a significant difference between the smolt and the smoltified groups (p < 0.05). An asterisk denotes significant differences between the groups.