Evidence for cell-replacement repair of X-ray-induced teratogenic damage in male genital imaginal discs of Drosophila melanogaster.
Male genital imaginal discs from old (late-third-instar) larvae of Drosophila that had been X-irradiated with appropriate doses developed into severely damaged adult genitalia when implanted into old larvae, but they developed into completely normal adult genitalia when transplanted into 2-day-younger larvae. The major cause of X-ray-initiated teratogenesis in the genital disc was DNA damage because development of the genital discs of strain mei-9a with defective DNA repair was twice as sensitive as that of the wild-type strain to impairment by X-irradiation, just as larvae of this strain were twice as sensitive to killing by X-irradiation as those of the wild-type strain. Complete repair of X-ray-induced teratogenic damage in the genital discs on transplantation into young host larvae was similar in the wild-type and mei-9a strains. These results are discussed in relation to the hypothesis that repair of X-ray-induced teratogenic damage depends not on DNA repair but on replacement of damage-bearing primordial cells by healthy ones after suicidal elimination of the former.
Fukunaga
A
A
Kondo
S
S
D000818:Animals; D004260:DNA Repair; D004307:Dose-Response Relationship, Radiation; D004331:Drosophila melanogaster / Q000166:cytology / Q000254:growth & development / Q000528:radiation effects; D005835:Genitalia / Q000002:abnormalities / Q000196:embryology / Q000528:radiation effects; D006358:Hot Temperature; D007814:Larva / Q000528:radiation effects*; D008297:Male; D014965:X-Rays