Reproduction Abstracts

Introduction: Mycotoxins, such as deoxynivalenol (DON), zearalenone (ZEN), and aflatoxin (AF), are commonly found in many food commodities and may impair the growth and reproductive efficiency of animals and humans. We investigated the effects of a mycotoxin-contaminated diet on mouse oocyte quality.

Materials and methods: Maize contaminated with DON (3.875 mg/kg), ZEN (1,897 μg/kg), and AF (806 μg/kg) was incorporated into a mouse diet at three different levels (0, 15, and 30%, w/w).

Results and discussion: After 4 weeks, oocytes from the mycotoxin-fed mice exhibited low developmental competence with reduced germinal vesicle breakdown and polar body extrusion rates, and the majority of embryos could not develop to the morula stage. Moreover, a large percentage of oocytes derived from mice that were fed a mycotoxin-contaminated diet exhibited aberrant spindle morphology, lower actin expression, a loss of the cortical granule-free domain, and abnormal mitochondrial distributions, which further supported the decreased oocyte quality. The fluorescence intensity analysis showed that the general DNA methylation levels increased in oocytes from high dose mycotoxin-fed mice. Mouse oocyte histone methylation was also changed, showing with altered H3K9, H4K20, H3K27, and H4K20 level. Thus, our results indicatethat naturally occurring mycotoxins have toxic effects on mouse oocyte quality.