Replication in UV-irradiated Caenorhabditis elegans embryos.
Replication continues in wild-type (but not rad mutant) Caenorhabditis elegans embryos even after exposure to massive fluences of UV radiation. It is of interest to elucidate the mechanism(s) for this "damage-resistant" DNA synthesis. In this study, DNA from unirradiated and UV-irradiated wild-type embryos was examined using the electron microscope. Large fluences of UV radiation (180 J m-2) had little effect on either replication bubble size or distances between bubbles in wild-type embryos, indicating that the damage-resistant DNA synthesis was not grossly aberrant. Conversely, UV irradiation significantly decreased center-to-center distances between bubbles in excision-repair-deficient rad-3 embryos. This suggests that the decreased DNA synthesis observed after UV irradiation in rad-3 embryos is due largely to blockage of elongation of DNA synthesis.
Jones
C A
CA
Department of Biology, Texas Christian University, Fort Worth 76129, USA.
Hartman
P S
PS
D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000528:radiation effects*; D004247:DNA / Q000096:biosynthesis / Q000528:radiation effects; D004261:DNA Replication / Q000528:radiation effects*; D014466:Ultraviolet Rays
D004247:DNA