Differential effect of ionizing radiation on transcription in repair-deficient and repair-proficient mice.
Experiments were designed to examine in vivo changes in total transcription and in the expression of the c-fos gene following whole-body exposure of mice to JANUS fission-spectrum neutrons. Radiation repair-deficient (wst/wst) and -proficient (wst/., C57BL/6 x C3H F1) mice were exposed to JANUS fission-spectrum neutrons calibrated to deliver a gut dose of 50 cGy. Animals were sacrificed less than 10 or at 60 min postirradiation, and gut tissues were removed for study. Our results revealed that, in repair-proficient mice, an immediate depression (relative to untreated control) in total transcription was evident that continued through 1 h postirradiation. Conversely, radiation-sensitive wst/wst mice displayed doubled transcription levels postirradiation. Expression of c-fos was consistently depressed following radiation exposure in control and wst/wst mice. However, the depression of c-fos mRNA was delayed in wst/wst mice relative to controls. These results demonstrate abnormal regulation of transcription and of c-fos mRNA accumulation in repair-deficient wasted mice following exposure to ionizing radiation. In addition, this work documents rapid total transcriptional depression in normal mice following radiation exposure.
Munson
G P
GP
Biological and Medical Research Division, Argonne National Laboratory, Illinois 60439.
Woloschak
G E
GE
D000818:Animals; D002467:Cell Nucleus / Q000528:radiation effects; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D004260:DNA Repair; D006579:Heterozygote; D007422:Intestines / Q000528:radiation effects; D051379:Mice; D008815:Mice, Inbred Strains; D008817:Mice, Mutant Strains; D009502:Neutrons; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016760:Proto-Oncogene Proteins c-fos; D011519:Proto-Oncogenes / Q000528:radiation effects*; D012313:RNA / Q000235:genetics / Q000302:isolation & purification / Q000528:radiation effects; D014158:Transcription, Genetic / Q000528:radiation effects*; D014916:Whole-Body Irradiation
D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D012313:RNA; D011505:Protein-Tyrosine Kinases