In Utero Exposure to Bisphenol A Disrupts Testis Development in Mouse Embryos

Embryonic exposure to estrogenic endocrine disruptors such as Diethylstilbestrol (DES) has been shown to result in abnormal gonadal development. Preliminary data from the Reproductive Developmental Biology group at NIEHS has shown that exposure to Bisphenol A (BPA) during mouse fetal development has led to underdevelopment of testes. This study aims to identify the effect of BPA exposure on the embryonic development of the mouse testis. The CD-1 mice model was used to investigate changes in morphology and gene expression. Four treatments were injected from embryonic day 10.5 to 17.5: two doses of BPA, a dose of DES and corn oil. The gonads of each embryo were collected at different pregnancy stages. One gonad was processed for RNA extraction and analysis via qPCR; the other processed for histological analysis. Results show that testes from fetuses exposed to BPA/DES showed varying degrees of testicular dysgenesis. The RNA analysis showed that DES/BPA exposure disrupted the expression of Estrogen Receptor alpha, Activin A and Insulin-like3. The gene expression analysis will seek to determine to what extent exposure to endocrine disruptors results in disregulation of the pathways necessary for testes development. Preliminary data suggests that in utero BPA exposure has an adverse effect on the embryonic development of the testes as shown by the histological and the gene expression analysis. This study may help understand the link between embryonic exposure to BPA in humans and potential abnormalities of the testes at early stages of gonadal development that may result in reproductive problems later in life.