Stage of susceptibility to carcinogenicity of prenatal dietary fat exposure tested by blastocyst transfer

A previous experiment with exposure of female mice to a diet high in fat from 4 weeks of age through to the end of pregnancy demonstrated a substantial increase in the frequency of reproductive system tumors in their female offspring. Over this wide period of exposure, one or more specific periods of sensitivity to the carcinogenic effects of dietary fat should exist. To test whether a high fat diet affects maternal germ cells and/or zygote development through to blastocyst formation, two blastocyst transfer experiments were performed. Blastocysts from a dam on high fat were transferred to a pseudopregnant dam on low fat. The reverse type of transfer was performed for contrast. These experiments did not reveal any significant effect of dietary fat on maternal germ cells or zygote development.