Effect of Zearalenone (ZEA) on Embryo Implantation in Mice.

Abstract

Embryo implantation is a prerequisite for successful reproduction in mammals. It is an endocrine-regulated process that can potentially be affected by endocrine disruptors. Zearalenone(ZEA) is an estrogenic mycotoxin produced by various species of Fusarium. It is widely distributed in livestock feed and also present in our food. It was reported that ZEA could impair fertility in farm animals, especially swine. Besides its effects on oocytes and embryo development, ZEA has also been shown to affect the uterus. It is hypothesized that ZEA can affect embryo implantation. C57/BJ6 mice are used to test our hypothesis. Naturally-mated females (8-12 weeks old) are administrated daily by gavage from gestation day 0.5 to 3.5 (D0.5-D3.5; mating night as day 0) for four consecutive days. The ZEA doses include 0, 1, 10, and 50 mg/kg body weight in 0.1 ml sesame oil. At D4.5, implantation sites are detected by Evan blue dye injection. Preliminary data show normal embryo implantation in the control group. However, no implantation sites are detected in the 50 mg/kg group (3/3) but all show abnormal embryos (fragmented or underdeveloped) in the oviducts. In the 10 mg/kg group, only one of five females shows normal implantation and the rest have no implantation sites, although healthy-looking blastocysts are present in their oviducts/uteri. In the 1 mg/kg group, three females have been examined. They show on-time implantation and even embryo spacing. The preliminary data collected so far indicate adverse effects of high doses of ZEA on embryo development, transport, and implantation. Embryo transfer will be employed to determine any adverse effects of ZEA on uterine receptivity in the high dose groups. (Supported by University of Georgia and NIH R15HD066301) (poster)