Figure 5

Representative TUNEL assays showing ( A-F ) the sustained radiation tolerance of early post-MBT embryos and ( G-R ) the effects of zygotic transgene expression in late post-MBT embryos derived from eggs of XR11 females. (A-F). Embryos were irradiated at stage 11.5 and fixed for TUNEL assay 12 hours later. A-C. GFP-negative embryos (lacking the XR11 transgene). A, Control. B, 10 Gy. C, 20 Gy. D-F. GFP-positive embryos (containing the XR11 transgene). D, Control. E, 10 Gy. F, 20 Gy. This experiment was conducted four times using eggs from six XR11 females. G-R. Embryos were irradiated in the mid-30 stages and fixed for TUNEL assay 12 hours later. G, H, K, L, O, P. GFP-negative embryos (lacking the XR11 transgene). G, H. Control. Small numbers of TUNEL-positive nuclei are evidence of spontaneous developmental apoptosis. K, L. 10 Gy. O, P. 20 Gy. I, J, M, N, Q, R. GFP-positive embryos (containing the XR11 transgene). I, J. Control. M, N. 10 Gy. The ventral pigmentation in Mis not due to TUNEL-positive nuclei. Q, R. 20 Gy. This experiment was conducted once using eggs from two XR11 females.