COMPARISON OF IN-VITRO DEVELOPMENT AND GENE-EXPRESSION OF IN VIVO-DERIVED AND IVM IVF-DERIVED PORCINE EMBRYOS AFTER MICROINJECTION OF FOREIGN DNA/

We compared the developmental ability and gene expression of in vivo- and IVM/IVF-derived porcine embryos following microinjection with SV40 -LacZ. A total of 412 IVM/IVF-derived and 129 in vivo-collected zygote s was used to examine developmental ability and gene expression follow ing DNA microinjection. When either DNA injected or noninjected zygote s were cultured for 4 d in NCSU 23 followed by 5 d in Eagle's minimal essential medium (EMEM), the percentages of zygotes developing to blas tocysts and hatched blastocysts were higher (P < 0.05) compared with g roups cultured in NCSU 23 alone. The percentages of injected embryos r eaching the morula and blastocyst stages were significantly lower (P < 0.05) than that of noninjected control embryos whether in vivo or IVM /IVF derived. The percentages of morula and blastocyst stage embryos e xpressing the gene were higher in the in vivo-derived embryos than in IVM/IVF-derived embryos. A lower proportion of (67 to 77%) mosaicism w as observed in the in vivo-derived embryos than in IVM/IVF (90 to 100% ) derived embryos. The total cell number of blastocysts cultured in bo th NCSU 23 and EMEM media was significantly higher than that of blasto cysts cultured continuously in NCSU 23. Our results suggest that this dual culture system enhanced embryo viability following microinjection of foreign DNA. (C) 1997 by Elsevier Science Inc.