The developing female genital tract: from genetics to epigenetics.

The mammalian female reproductive tract develops from the Mullerian ducts which differentiate, in a cranial to caudal direction, into oviducts, uterine horns, cervix and the anterior vagina. The developmental processes taking place during this organogenesis are notably under the control of steroid hormones, such as members of the Wnt and Hox families, which regulate key developmental genes. At later stages, steroid hormones also participate in the development of the female genital tract. Chemical compounds homologous to steroids can thus act as agonists or antagonists in fetuses exposed to them. These so-called endocrine disruptors are nowadays found in increasing amounts in the environment and may therefore have a particular impact on such developing organs. Epidemiological studies have revealed that endocrine disruptors have had drastic effects on female health and fertility during the last decades. Furthermore, these adverse effects might be transmitted to subsequent generations through epigenetic modifications. Given the potential hazard of inherited epigenetic marks altering reproduction and/or human health, such molecular mechanisms must be urgently investigated. This review aims to summarize the cellular and molecular mechanisms involved in female genital tract development, to highlight key genes involved in this process and to present epigenetic mechanisms triggered by endocrine disruptors and their consequences in regard to female reproductive tract development.