Abstract
Frog eggs γ-irradiated before insemination developed normally during the early stages, and then most of them became abnormal embryos. From the remainings a few metamorphosed haploid frogs and a few non-viable haploid tadpoles were obtained.
The transfers in which the cytoplasm had been irradiated and the nucleus was introduced from a normal blastula cell were very low in developmental capacity, as compared with the control transfers whose cytoplasm and nucleus had not been irradiated. However, two metamorphosed frogs and a tadpole were obtained from among rN transfers.
All the transfers in which the cytoplasm was normal and the nucleus was introduced from an irradiated blastula cell did not develop beyond the heart-beat stage, as irradiated blastulae did not.
