Gamma-ray-induced numerical and structural chromosome anomalies in mouse immature oocytes.
Young female mice were given 1, 2 or 3 Gy of chronic gamma-irradiation. Metaphase II oocytes from these mice were sampled 8 weeks after the end of the treatment and screened for numerical and structural chromosome anomalies. The proportions of hyperhaploid (n + 1) metaphase II oocytes increased after 1 and 2 Gy (significantly after the latter) but remained at the control level after 3 Gy of gamma-rays. Structural chromosome anomalies were significantly increased above control levels at all doses and also showed an increase with dose to 2 Gy and a decline at 3 Gy. The cause of this unusual dose-response pattern for induced chromosome damage is uncertain. These results show that significant chromosome damage can be induced by irradiation of immature oocytes, a cell stage previously suggested to be resistant to induced genetic damage.
Griffin
C S
CS
M.R.C. Radiobiology Unit, Didcot, Oxon, Great Britain.
Tease
C
C
D000782:Aneuploidy; D000818:Animals; D002869:Chromosome Aberrations; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D008540:Meiosis / Q000528:radiation effects; D051379:Mice; D009154:Mutation / Q000528:radiation effects*; D009865:Oocytes / Q000528:radiation effects*; D009866:Oogenesis / Q000528:radiation effects; D014916:Whole-Body Irradiation