Evaluating an in vitro culture system of bovine uterine and oviduct epithelial cells for subsequent embryo co-culture

Abstract

Three experiments were conducted to evaluate the effects of culture medium and incubation temperature on bovine uterine and oviduct epithelial cell growth, so that the most efficient combination could then be used to develop a co-culture system for bovine embryos. In the first experiment, uterine and oviduct epithelial cells at either the second or third subpassage were incubated for 8 days at 37 degrees C with 5% CO2 in Tissue Culture Medium-199, CMRL-1066, Minimal Essential Medium, Menezo's B2 or Ham's F-12 medium. In addition to plotting growth curves of cell populations, the cell cycle was monitored for 8 days by flow cytometry. Uterine and oviduct epithelial cells incubated in CMRL-1066 exhibited the highest growth rates during the 8-day culture period. However, there were no differences in cell cycle analysis among treatment groups during the incubation period. In the second experiment, CMRL-1066 medium was used to evaluate growth and proliferation of uterine and oviduct epithelial cells incubated at 37 degrees C or 39 degrees C; temperature had no significant effect on growth rates or proliferation rates for either uterine or oviduct cells during the 8-day incubation. In the third experiment, the more promising culture media for epithelial cell culture studies were chosen for in vitro maturation and subsequent in vitro fertilization (IVF) of bovine oocytes. Early cleavage-stage embryos produced by IVF procedures were subsequently cultured in vitro for 7 days in medium alone or with oviduct epithelial cells. In this study, the culture medium did not influence fertilization or cleavage rates. However, more embryos co-cultured with oviduct epithelial cells were considered viable after 7 days of incubation compared with embryos incubated in medium alone. These results indicate that various incubation conditions can influence the growth of bovine uterine and oviduct epithelial cells in vitro. However, in spite of changes in cell growth patterns, there does not appear to be a change in their embryotropic capabilities in vitro.