Impact of genistein on maturation of mouse oocytes, fertilization, and fetal development.

Genistein (GNT), a natural isoflavone compound found in soy products, affects diverse cell functions, including proliferation, differentiation and cell death. An earlier study by our group showed that GNT has cytotoxic effects on mouse blastocysts and is associated with defects in their subsequent development in vitro. Here, we further investigate the effects of GNT on oocyte maturation, and subsequent pre- and postimplantation development, both in vitro and in vivo. GNT induced a significant reduction in the rate of oocyte maturation, fertilization, and in vitro embryo development. Treatment of oocytes with GNT during in vitro maturation (IVM) led to increased resorption of postimplantation embryos, and decreased placental and fetal weights. With the aid of an in vivo mouse model, we showed that consumption of drinking water containing GNT led to decreased oocyte maturation and in vitro fertilization, as well as early embryonic developmental injury. Moreover, our findings support a degree of selective inhibition of retinoic acid receptors in blastocysts treated with GNT during oocyte maturation. To our knowledge, this is the first study investigating the impact of GNT on maturation of mouse oocytes, fertilization, and sequential embryonic development.