[Expression of recombinant DNA RSVlacZ and pCMVlacZ in preimplantation rabbit embryos]

A linear fragment of the pRK3lacZ plasmid (RSVlacZ) and circular DNA of pCMVlacZ were injected into rabbit zygotes. The embryos were cultured for 24-72 h and analyzed with chromogenic X-gal substrate for bacterial beta-galactosidase. The expression of RSVlacZ DNA was revealed in 6-16-cell embryos. The expression of pCMVlacZ plasmid was low in 2-blastomere embryos, and high in 4-16-cell embryos. In both cases, no beta-galactosidase activity was observed in one-cell embryos. The results obtained indirectly suggest selective and stepwise gene activation in the course of rabbit embryo development.