Cytogenetic studies in mouse oocytes irradiated in vitro at different stages of maturation, by use of an early preantral follicle culture system

Paul Jacquet, Iris Adriaens, Jasmine Buset, Mieke Neefs, Sarah Baatout, Max Mergeay

    Research outputpeer-review


    In vivo studies on X-irradiated mice have shown that structural chromosome aberrations can be induced in female germ cells and that the radiation-induced chromosomal damage strongly depends on the stage of maturation reached by the oocytes at the time of irradiation. In the present study, the sensitivity of oocytes to radiation-induction of chromosome damage was evaluated at 2 different stages, using a recently developed method of in vitro culture covering a crucial period of follicle/oocyte growth and maturation. A key feature of this system is that growth and development of all follicles is perfectly synchronized, due to the selection of a narrow class of follicles to start-off culture. This allows irradiation of well characterized and homogenous populations of follicles, in contrast to the situation prevailing in vivo. Follicles were X-irradiated with either 2 or 4 Gy, on day 0 of the culture (early preantral follicles with 1-2 cell layers) or on day 12, 3 h after hormonal stimulation of ovulation (antral Graafian follicles). Ovulated oocytes, blocked in MI by colchicine, were fixed 16 h after hormonal stimulation and analyzed for chromosome aberrations. The results confirmed the high radiosensitivity of oocytes 2 weeks prior to ovulation and the even higher radiosensitivity of those irradiated a few hours before ovulation, underlining the suitability of the in vitro system for further studies on the genetic effects of ionising radiation in female mammals.
    Original languageEnglish
    Pages (from-to)168-177
    JournalMutation Research
    StatePublished - 2005

    Cite this