Anatomical and Histological Changes of Reproductive Organs in Japanese Quail (Coturnix japonica) Embryos after in ovo Exposure to Genistein

Genistein, an isoflavonoid phytoestrogen, has a similar structure to endogenous estrogen and is also able to produce estrogen-like effects. Administration of exogenous estrogens as well as phytoestrogens causes reproductive abnormalities in adult birds. Here, we examine whether genistein affects reproductive organ development in Japanese quail at the sexually differentiated stage. Genistein (16 and 24 μg/g egg) was injected into the yolk via the blunt end of the fertilized egg prior to incubation. Both concentrations caused Mullerian duct abnormalities in both sexes and ovotestis formation in male embryos. This is the first report that genistein affects reproductive organ development in avian embryos.