Animal procedures in this study were approved by the Institute Animal Care and Use Committee at the National Health and Environmental Effects Research Laboratory (NHEERL) of the United States Environmental Protection Agency. Timed pregnant CD-1 mice were mated at Charles River Laboratories, Inc. (Raleigh, NC) and delivered to the NHEERL animal facility on Gestation Day (GD) 6. Dams were housed five per cage on laboratory grade pine shavings (Northeastern Products, Warrensburg, NY) in clear polycarbonate boxes until GD 17, when they were individually housed.
They were housed under controlled temperature (22°C ± 1°C), relative humidity (50% ± 10%) and light (12L:12D, lights out at 1800 h). They were provided an ad libitum diet of rodent chow (RMH3000; PMI Nutrition International, Inc., Bentwood, MO) and tap water. For fertility studies, male CD-1 offspring (PND 72) previously exposed in utero were housed individually, and virgin female mice (8-10 wk) were initially housed 10 per cage. During the fertility study, two female mice were cohabited with one male mouse.