The effect of low-dose X-irradiation on numerical and structural chromosome anomaly induction in mouse immature oocytes.
The ability of low doses of X-rays to induce numerical and structural chromosome anomalies in immature oocytes was examined in two experiments. In the first, 10-11-day-old females were given 0.1 or 0.2 Gy of X-rays and sampled at intervals up to 32 weeks later. In the second, 4-5-week-old females were given 0.1 Gy of X-rays and sampled up to 36 weeks post-irradiation. Chromosome anomalies were assessed in metaphase II oocytes. In the first experiment, there was evidence of dose-related increases in both hyperhaploidy (n + 1) and structural chromosome anomalies. In the second experiment, only the frequency of structural chromosome anomalies was found to increase consistently after irradiation. There was no indication that radiation-induced depletion of the oocyte population was associated with an early onset of the maternal age effect on nondisjunction.
Griffin
C S
CS
M.R.C. Radiobiology Unit, Chilton, Didcot, Oxon, Great Britain.
Tease
C
C
Fisher
G
G
D000704:Analysis of Variance; D000818:Animals; D002869:Chromosome Aberrations; D002875:Chromosomes / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006238:Haploidy; D051379:Mice; D009865:Oocytes / Q000648:ultrastructure*