ABSTRACT
Analogous to mice and rat models, many researchers have shown that transgenic pigs can be produced by injecting DNA into the pronucleus of fertilized eggs (for a review,
see Nottle et al., 1997). However, harvesting embryos at the pronuclear stage is labor-and cost-intensive. In our largescale study (Nottle et al., 1997), only 10.7 pronuclear stage embryos that were suitable for DNA injection could be obtained on average from each embryo donor pig that had been treated by superovulation. Without a revolution in the technique of superovulation, the production of transgenic minipigs by injecting DNA into the pronucleus of fertilized eggs will remain impractical.
