DNA reduplication during meiotic prophase in the oocytes of Carausius morosus Br. (Insecta,Cheleutoptera)

Cytological investigations combined with cytophotometric DNA determinations on Feulgen stained squash preparations of ovarioles from third and fourth instar nymphs of Carausius morosus revealed that during meiotic prophase a largely despiralized stage follows pachytene and that in this stage an extra reduplication of the nuclear DNA takes place (pachyreduplication phase). Meiotic prophase then proceeds with tetrapachytene, a pachytene-like stage with twice the amount of DNA as compared to oocyte nuclei in earlier meiotic stages, and with more than half the somatic number of elements, being probably autobivalents.Supported by Deutsche Forschungsgemeinschaft.