Temporal effect of human oviductal cell and its derived embryotrophic factors on mouse embryo development

Mouse embryos at different stages of development were cocultured with human oviduct cells or cultured in the presence of oviduct-derived embryotrophic factor-1, -2, and -3 (ETF-1, -2, and -3) for various amounts of time withi n the preimplantation period. Cocultures that included the period from 48 t o 72 h post-hCG stimulated cell division and increased the cell numbers in the inner cell mass (ICM) of the exposed blastocyst. Exposure of embryos to oviductal cells from 96 to 120 h post-hCG increased the cell number in the trophectoderm (TE), blastocyst size, hatching rate, attachment, and in vit ro spreading of the blastocyst. ETF-1 and ETF-2 affected embryos between 48 and 72 h post-hCG by increasing the number of cells in the ICM. In contras t, ETF-3 had a more profound effect on embryos that were exposed from 96 to 120 h post-hCG, where it mostly affected the development of TE cells, lead ing to higher hatching rate. Human oviductal cells improved mouse embryo de velopment partly by the production of high molecular weight embryotrophic f actors. These factors had differential effects on mouse embryo development.