Influence of Uterine Position on the Response of the Mouse Embryo to the Teratogenic Effects of Hyper-vitaminosis-A

Abstract

WHEN a teratogenic agent is administered to a number of pregnant mammals of a single species under identical conditions of timing and dosage, its effect on the development of the young is by no means uniform. In any individual litter, all, none or a proportion only of the young may be deformed. Even when a highly inbred strain is used, variations in the response to the teratogenic agent may be attributable to differences in the maternal genotype. Such differences cannot, however, be held responsible for the situation in which individual members of a litter develop normally while others are deformed. The differences in response of litter mates must derive either from individual variations in genetic make-up or from environmental factors as yet unanalysed. The present investigation was carried out in order to determine the influence of a single environmental factor, namely, the site of implantation, on the susceptibility of the mouse embryo to the teratogenic effects of hypervitaminosis-A.