[Studies on the early development of nucleocytoplasmic hybrid embryos between mouse and rabbit by nuclear transplantation].

Nuclear transplantation has been proved to be a very powerful method in researching the relationship between nucleus and cytoplasm during embryogenesis. Electrofusion is a new means of cell fusion which is being improved in the past nearly ten years. In this study, we produced interorder nucleocytoplasmic hybrid embryos between mouse and rabbit with these two techniques. Two phenomena, i.e. premature chromosome condensation (PCC) and nuclear swelling, were observed after mouse 8-cell stage blastomeres were fused into rabbit enucleated oocytes. After 4.5-days cultured in mouse oviducts, 5.4% reconstituted embryos developed into blastocysts. By karyotype examination, it was known that only mouse chromosomes were presented in the blastomeres, one blastocyst even had a normal mouse karyotype (2 n = 40, XX). As a conclusion, we consider it is possible to obtain normal early development of interspecies nucleocytoplasmic hybrid embryos between mouse and rabbit.