Pseudo dominant-lethal response in female mice treated with plant oils

Corn oil, sesame oil, peanut oil, or olive oil, injected intraperitoneally to female mice prior to insemination, increased the number of deciduomata. In many plant oil-treated females the number of implantation sites was markedly higher than corpora lutea count. These effects were not observed among females that were treated similarly with mineral oil or among females that were given corn oil via oral administration. Evidence indicates that these effects did not arise from induced dominant-lethal mutations but from decidual responses resulting from traces of oil reaching the uterine lumen.