IN-VITRO DEVELOPMENT OF DNA-INJECTED EMBRYOS COCULTURED WITH GOAT OVIDUCT EPITHELIAL-CELLS IN KOREAN NATIVE GOATS (CAPRA-HIRCUS AEGAGRUS)

In vitro development of Korean native goat embryos was investigated in 2 different culture systems with and without goat oviduct epithelial cells (GOEC). Estrus was synchronized by inserting intravaginal proges tagen-impregnated sponge (Veramix) containing 60 mg medroxyprogesteron e acetate (MAP) for 14 d. Superovulation was induced with follicle sti mulating hormone (FSH). Goat ova were surgically obtained by retrograd e flushing the oviducts of does at 66 to 68 h after MAP removal. Mean number of recovered ova per doe was 7.28+/-3.91, and the proportion of fertilized embryos in recovered ova was 66.5% (121/182). Fertilized e mbryos were cultured for 9 d in CR1aa medium supplemented with 10% est rous goat serum (EGS) at 38.5 degrees C, 5% CO2 in air. There was no d ifference in development of the embryos to the morula stage between th e 2 culture systems (84.4 and 84.0%, respectively). However, developme ntal rate to blastocysts (65.6%) of the embryos co-cultured with GOEC was significantly higher than of those (12.0%) cultured without GOEC ( P<0.001). Goat zygotes were injected with bovine beta-casein/human lac toferrin cDNA fusion gene (pBL1). When the DNA-injected embryos were c o-cultured with GOEC, developmental rates of the embryos to the morula and blastocyst stages were 82.9 and 36.6%, respectively. The results obtained in this study indicate that ''blocking'' of in vitro developm ent of Korean native goat embryos appears to occur at the morula stage , but can be overcome to some extent by co-culture with GOEC. In the c o-culture system, DNA-injected goat embryos could successfully develop to normal hatching blastocysts. (C) 1997 by Elsevier Science Inc.