• nuclear transfer;
  • mouse embryo;
  • surface antigens


The ability of foreign nuclei to support development in nuclear transplantation manipulations has proven an effective means to assess the consequences of nuclear differentiation. In addition, nuclear transplantation might serve to define the persistence and role of maternally inherited cytoplasmic constitutents during embryogenesis. We have extended the use of a technique that enables the efficient transfer of one-cell-stage pronuclei into the cytoplasm of enucleated mouse embryos, and have successfully transferred two-, four-, eight-cell-stage and inner cell mass (ICM) cell nuclei. We have also used this technique as a means to determining that the stage-specific embryonic antigen, SSEA-3, is a cytoplasmic contribution of the unfertilized ovum. The potential value of this technique in determining the developmental capacity of nuclei from various embryonic stages, and in determining nuclear/cytoplasmic origins of early embryonic gene products, is discussed.