Effects of gamma-irradiation on the yield of mid-ventral white spots in mice in different genetic backgrounds and at different times during development.
Pregnant females C57BL/10JHir-p/p mice crossed with C57BL/10JHir males were whole-body irradiated with a single acute dose of 60Co-gamma-rays to investigate the effect of gamma-radiation on embryonic melanoblasts. The effect was studied by scoring changes in the cutaneous coats of F1 offspring 25 days after birth. White spots were found in mid-ventrum of the animals. Melanoblasts and melanocytes were not observed in the spotted skin. The frequency of the spots increased in a dose-dependent manner. White spots were found in mid-ventrum of (C57BL/6J female x C3H/HeJmsHir male) F1 exposed to gamma-rays. However, the frequency of the spots in (C57BL/6J female x C3H/HeJmsHir male) F1 were extremely lower than that in (C57BL/10JHir-p/p female x C57BL/10JHir male) F1, suggesting the possibility that the frequency of mid-ventral white spots are genetically controlled. Moreover, the highest frequency was found in (C57BL/10JHir-p/p female x C57BL/10JHir male) F1 irradiated at 8.5 days of gestation. This stage corresponds to the stage of initiation of neural-crest cell migration. These results indicate that gamma-radiation affects the differentiation of melanocytes in the skin both with genetical control and with greater effects seen at the stage of initiation of neural-crest cell migration.
Hirobe
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Division of Biology, National Institute of Radiological Sciences, Chiba, Japan.
D000818:Animals; D003037:Cobalt Radioisotopes / Q000009:adverse effects*; D004307:Dose-Response Relationship, Radiation; D004622:Embryo, Mammalian / Q000528:radiation effects*; D005260:Female; D005720:Gamma Rays / Q000009:adverse effects; D005865:Gestational Age; D008297:Male; D008544:Melanocytes / Q000528:radiation effects; D051379:Mice; D008815:Mice, Inbred Strains; D012867:Skin / Q000166:cytology / Q000528:radiation effects*; D013045:Species Specificity
D003037:Cobalt Radioisotopes