Abstract
The present study was undertaken to confirm the report of MCGRATH & SOLTER (1983) who sucess-fully transplanted single pronucleus between one-cell stage eggs using inactivated sendai virus (HVJ).
One or two pronucleus was removed and discarded in a manner which the pipette did not pene-trate the ovum plasma membrane (recipient egg). The pronucleus (ei) was also removed from donor egg in the same way, then a small volume of HVJ was drawn into the pipette.
The recipient egg was held by a suction pipette with the previous site of encleation, and HVJ and karyoplast were in-jected into perivitelline space. The results obtained are as follows.
1) The proportion of fused eggs with karyoplast were 92% and 90% for single or both pronuclei transplantation.
2) The proportion of eggs developed to morula or blastocyst stage was 78 to 87%.
3) The proportion of single and both pronuclei transplant eggs that successfully developed to term was 11% and 19%, respectively.
So far as we know, the present study was the first report for successful pronucler transplanta-tion in mammalian eggs in Japan.
