Effects of low molecular weight oviductal factors on the development of mouse one-cell embryos in vitro

Abstract

The relationship between the oviduct and embryo development in the mouse was investigated and the period at which the influence of oviduct can be concerned in the development of mouse embryos in vitro was identified. In addition, the relative molecular weight of oviductal factors that promote embryo development was demonstrated. Mouse zygotes developed to the blastocyst stage when co-cultured with ampulla. The period of embryo co-culture significantly affected the further development of the embryos. Fewer one-cell embryos co-cultured with dissected ampullae for less than 24 h developed to blastocysts than those co-cultured for more than 28 h (P < 0.001). A high percentage of embryos co-cultured with ampullae after 24 h of culture in vitro developed to the blastocyst stage, which suggests that the influences of ampulla on the development of mouse embryos are restricted to a specific period at the two-cell stage (about 55-56 h after hCG injection) in vitro. Mouse ova that were cultured in media conditioned by ampullae could also develop to the blastocyst stage. The fractionated medium that contained low molecular weight fractions was more effective (P < 0.001) on the development of embryos to the blastocyst stage than that containing high molecular weight fractions. These results suggest that the low molecular weight oviductal factors play an important role in the development of mouse embryos at a certain critical age in vitro.

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

“…In contrast, the benefits observed using MDBK cells were lost with Vero cells, suggesting either that some cell lines are unable to remove inhibitory factors from a poor medium such as B2 or that inhibiting factors are produced by certain cell lines. In addition, contrary to studies reporting the existence of a low molecular weight molecule which enhanced embryo development (Minami et al, 1992;Mermillod et al, 1993), no beneficial effect was consistently observed in any specific fraction tested in our work. This supports the idea that cells are responsive only to certain media and that feeder cells do not improve embryo development through specific factors secreted into the medium but only act by changing the base medium.…”

“…In the light of this, several studies have argued that a number of different cell lines may produce such a factor(s) Ouhibi et al, 1990;Minami et al, 1992;Bongso et al, 1993;Mermillod et al, 1993). In this study only B2 medium conditioned by MDBK cells improved embryo development, but no blastocyst formation was observed in B2 alone.…”

Morphological and functional characterization of bovine oviductal epithelial cell monolayers cultured on polarizing membranes

“…These granules seem to be those described in semi-thin sections as basophilic bodies which, at high magnification, appear surrounded by a limiting membrane and composed of fine, granular, electron-dense material (fig 9 and 11). These (Minami et al, 1992) and more recently in human oviductal cells (Liu et al, 1995 (Takahashi and First, 1992), some toxic components of M-199 as hypoxanthine (Loutradis et al, 1987), phosphate (Pinyopummintr and Bavister, 1991) and superoxide radicals (Noda et al, 1991). Low molecular weight antioxidants, as taurine (Tiffin et al, 1991) and gluthatione (Legge and Sellens, 1991), could also have been secreted into the medium.…”

Embryo Culture in Explanted Oviducts in Mice and Cattle

“…Development of one-cell embryos to blastocyst was sig nificantly enhanced by culture in conditioned medium [19], suggesting that some factors in conditioned media are effective for embryonic development. The existence of oviduct-specific glycoproteins has been demonstrated in mice [20], hamsters [21], rabbits [22], sheep [23,24], baboons [25] and cattle [26], but the biological functions of these molecules remain to be clarified.…”