Co-culture of 1-cell mouse embryos on different cell supports

Abstract

The development of 1-cell mouse embryos in explanted oviducts, on mouse and bovine oviduct epithelial cells and on two established cell line supports is compared. The best rates of blastocyst formation were obtained using explanted oviducts; mouse and to a lesser extent, bovine oviduct epithelial cells allow good embryonic development, associated with high viability after transfer of the blastocysts obtained in co-culture. MDBK (from bovine kidney) and Vero (from Green monkey kidney) have been tested. MDBK allows high rates of blastocyst formation (67%) and the blastocysts obtained are viable. Vero does not allow the 2-cell block to be overcome. Maintenance of cell polarity for all the feeder layers did not improve embryo development. A preliminary study on the metabolic modifications induced by the feeder layers showed no modifications at all related to a decrease in glucose, an increase in lactate and early embryonic development. On the other hand, for the free amino acids, cellular supports with high embryotrophic activity seem to mimic tubal secretions, especially with a high level of glycine. Neither a genital tract origin, nor a hormonal contribution are strictly necessary for embryo co-culture, as already demonstrated by co-culture with trophoblastic tissue. Established cell lines, which are easy to handle and control, could be useful tools in embryo biotechnology.

Fertilization and early embryology: Differential effect of epithelial cell-conditioned medium fractions on preimplantation mouse embryo development

“…In contrast, control 2-cell embryos cultured in T6VA in parallel developed to blastocysts at a high rate (46/60, 76.7%). These experiments confirmed previous results in which coculture of 2-cell mouse embryos on Vero cells using B2 led to poor blastocyst development (8%) (Ouhibi et al, 1990).…”

“…In 1987, Gandolfi and Moor successfully used coculture with sheep oviduct epithelial cells to improve the culture and viability of sheep embryos. Similar studies were subsequently conducted by Eyestone and First (1989) in cattle, Ouhibi et al (1990) and Sakkas and Trounson (1990) in mice and Sakkas et al (1989b) in goats. In the human, coculture using Fallopian tube cells (Bongso et al, 1989;Yeung et a/., 1992) and bovine uterine fibroblast cells (Wiemer et al, 1989) has been reported to improve pregnancy rates; however, the use of controlled epithelial cell lines is more ethically acceptable due to the possibility of introducing viruses and infecting the patient's embryo.…”

“…For example, Gandolfi and Moor (1987) showed that coculture with oviduct cells enhanced cleavage-stage sheep embryo development compared to culture medium without cells. A positive effect from coculture has also been shown by Menezo et al (1990) in human embryo development and by Ouhibi et al (1990) and Lai et al (1992) in mouse. At the same time, similar experiments using IVF bovine embryos in coculture with oviduct cells using TCM199 without FCS (Pinyopummintr and Bavister, 1991) failed to show any benefit from coculture.…”

“…In coculture with Vero cells, Menezo et al (1990) and Ouhibi et al (1990) observed beneficial effects of Vero cells on coculture of human embryos but not with 1 -cell mouse embryos. In contrast, Lai et al (1992) reported mouse embryo development from the 2-cell stage until the blastocyst stage using Vero cells.…”

“…These cells have previously been reported to improve embryo development (Ouhibi et al, 1990;Lai et al, 1992) and share the same embryonic origin (mesoderm) with oviduct cells. To maintain the cell lines we used Dulbecco's modified Eagle's medium (DMEM; Gibco) with 10% FCS.…”