In Vitro Development of Goat Embryos: Effect of Co-culture with Oviductal Epithelial Cells

Development of reliable in vitro culture systems to produce high percentages of viable embryos is instrumental in the application of biotechnologies such as cloning and transgenesis. This is especially true for caprine species in which in vitro technology for embryo culture has been poorly developed. The objective of this study was to compare in vitro development of in vivo fertilized caprine embryos in: a) coculture with caprine oviductal epithelial cells (OEC), b) synthetic oviduct fluid (SOF), or c) medium conditioned by oviductal epithelial cells (CM). In vivo fertilized 1-8 cell caprine embryos collected by oviductal flushing were allocated to treatments and cultured for 4-5 days in vitro. At the end of the culture period, embryonic development was recorded and the number of cells per embryo was determined in lacmoid-stained embryos. A significantly higher percentage of embryos reached the morula/blastocyst stage in coculture compared with those cultured in SOF (75% vs. 41% respectively; P < 0.05) or CM (5.5%); SOF was superior to CM to supporting goat embryo development. Likewise, embryos grown in coculture with OEC had more cells than those cultured in SOF (15.3 vs. 8.1 cells/embryo; P < 0.05). Cell counts were higher in embryos cultured in SOF than those originated from CM. In conclusion, coculture of goat embryos with OEC provided superior conditions to support in vitro development of early-stage goat embryos compared with the other treatments studied.