Analysis of post-implantation mouse embryos after maternal heat stress during meiotic maturation.
The effects of heat stress during oocyte maturation were studied in post-implantation mouse embryos. Virgin ICR mice were exposed to 35 +/- 1 degree C and 65 +/- 3% RH for 12.5 h beginning immediately after synchronization of ovulation with PMSG and hCG. Embryos of heat-stressed dams were developmentally heterogeneous and showed significant delays in development with as much as 48 h delayed development. Nearly 6% of these embryos were triploid, and another 2% were hyper-diploid. Development of triploid embryos was delayed more than 24 h. Nine embryos with severe developmental delay had heterogeneous chromosome constitutions. Embryo mortality before and after implantation was higher in heat-stressed dams than in controls.
Baumgartner
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AP
Department of Animal Sciences, Purdue University, West Lafayette, Indiana 47907.
Chrisman
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CL
D000818:Animals; D005314:Embryonic and Fetal Development; D005260:Female; D005313:Fetal Death; D006358:Hot Temperature / Q000009:adverse effects*; D008540:Meiosis; D051379:Mice; D008813:Mice, Inbred ICR; D009865:Oocytes / Q000166:cytology; D011247:Pregnancy; D013312:Stress, Physiological