X-ray-induced chromosome aberrations in immediately preovulatory oocytes

The effects of relatively small doses of X-rays (up to 100 cGy) to immediately preovulatory mouse oocytes have been examined by screening chromosome aberrations at metaphase I. Dose-related responses for the induction of aberrations were found. These were mainly of the quadratic or power-law types, and therefore similar in nature to the dose-responses described elsewhere for dictyate oocytes. The frequencies of the various categories of structural aberration have been compared to the previously determined rates of radiation-induced non-disjunction in immediately preovulatory oocytes in order to examine the potential involvement of structural chromosome aberrations in radiation-induced non-disjunction.