Established cell lines and their conditioned media support bovine embryo development during in-vitro culture.

These experiments were conducted to evaluate the ability of different somatic-cell monolayers or conditioned medium from somatic cells for supporting bovine embryo development in vitro. In the first experiment, bovine embryos (2- to 4-cells) were allocated randomly to a control (medium 199 with 10% fetal bovine serum and antibiotics) group or co-cultured with bovine oviduct epithelial (BOEC), buffalo rat liver (BRL), Madin Darby bovine kidney (MDBK) or African green monkey kidney (Vero) cells. In the second experiment, bovine embryos (1-cell) were allocated randomly to the following groups: control medium or conditioned medium from BOEC, BRL, MDBK and Vero monolayers. In both experiments, development to the blastocyst stage was assessed after 8 days of incubation at 39 degrees C and 5% CO2. In Experiment 1, coculture improved development to the blastocyst stage compared with control medium alone, and the highest development was observed after co-culture with BOEC. In Experiment 2, conditioned medium enhanced development to morulae and blastocysts compared with the control medium; however, no differences were detected among different cell supports. These results indicate that both co-culture and conditioned medium from different cell monolayers supported development to the blastocyst stage at a higher efficiency than control medium alone.