Figure 2.

Effects of swimming exercise on the expression of estrogen receptor 1, vitellogenin1 and vitellogenin2. Relative expression of estrogen receptor 1, vitellogenin1 and vitellogenin2 (fold change fc of swimmers vs. resters) after a) swimming for 1.5 and 3 months (-CPE), and b) after subsequent stimulation with three weekly CPE injections (+CPE). Asterisks indicate a significant difference (P < 0.05) in ng mRNA of a swim group vs. the rest group. Expression of all genes is reduced after swimming 1.5 months and more after swimming 3 months vs. expression in the resting eels (fc<1). CPE treatment compensates for these differences equalizing the initial differences between resting and swimming (fc>1).