Oral Presentation The Joint Annual Scientific Meetings of the Endocrine Society of Australia and the Society for Reproductive Biology 2017

Paternal atrazine exposure affects mouse pre-implantation embryo characteristics (#131)

Alesia P Harper 1 , Bethany J Finger 1 , Andrew J Pask 1 , Mark P Green 1
  1. School of BioSciences, University of Melbourne, Melbourne, VIC, Australia

Exposure to endocrine disrupting chemicals is becoming increasingly common and is associated with a growing number reproductive diseases. Atrazine is one of the most commonly used herbicides in Australia, and is known to have endocrine disrupting effects. Atrazine is found in waterways around Victoria and is of concern to the health of both humans and local wildlife. Past research on the effects of atrazine exposure in mammals has largely focused on high experimental doses over a short-time period and very few have considered how chronic exposure of atrazine may affect the reproductive output of male mammals, including humans. Therefore, the aim of this study was to determine if chronic paternal exposure to atrazine would affect pre-implantation embryo development in mice. C57BL6J male mice were exposed via drinking water to atrazine (5mg/kg/day, n=10) or no atrazine (n=9) from day E9.5 to 12 weeks of age. Male body weights were recorded for the duration of the experiment. At 12 weeks of age mice were mated to unexposed superovulated females and the embryos were collected, cultured in vitro, development rates were recorded and day 5 embryo cell numbers assessed by a differential staining (n=128). The effect of atrazine exposure on body weight gain, plug rate, fertilisation rate and blastocyst formation did not differ between groups (P>0.1). However, both inner cell mass (control: 31.4 ± 1.7, atrazine: 27.8 ± 1.0, P=0.05) and total cell numbers (control: 94.3 ± 4.1, atrazine: 85.6 ± 2.0, P=0.04) were lower in embryos from atrazine exposed fathers. These data demonstrate that exposure to chronic low doses of atrazine can influence pre-implantation embryo characteristics. Further studies are ongoing to determine the possible mechanisms, long-term implications on embryo health and effects of chronic atrazine exposure on male fertility.