Figure 4

Maternal and paternal expression of the XR11 transgene. A-F. Maternal expression of the XR11 transgene reduces the extent of apoptosis in embryos exposed to γ-radiation at stage 6–6.5 and examined 12 hours after irradiation by whole-mount TUNEL assays. A-C, Wild-type embryos. A, Representative control embryos. Arrow indicates the blastopore lip. No evidence of apoptosis is apparent. Embryos that had been exposed to 10 Gy are shown in B. More extensive damage is seen after exposure to 20 Gy (C). D-F, TUNEL assays of progeny of fertilization of XR11 eggs by wild-type sperm after exposure to either 10 Gy (E) or 20 Gy (F). This experiment was conducted three times using eggs from four XR11 females. G-L. Paternal expression of the XR11 transgene does not protect embryos from apoptosis induced by γ-radiation before the MBT. Representative whole-mount TUNEL assays comparing the effects of γ-radiation at stage 6–6.5 on wild-type embryos (G-I) and progeny of fertilization of wild-type eggs by XR11 sperm (J-L). Embryos were fixed for TUNEL assay 12 hours after irradiation. G, J. Controls. H, K. 10 Gy. I, L. 20 Gy. This experiment was conducted twice using sperm from two XR11 males.