DNA methylation epigenetic changes were analysed in Daphnia magna exposed for 25-day to chronic gamma irradiation compared to unexposed controls. Generation F0 were exposed to 6.5 µGy/h or 41.3 mG/h and let recoverd until the F3 generation without exposures to ionizing radiations. DNA-methylation patterns were analysed by WGBS on the whole organismes at the generation F0, F2 and F3 in order to detect possible transmission of DNA methylation changes to the progeny. Overall design: Biological samples (whole adults) were analysed by WGBS