Embryo development under the effects of a new placental protein (UTPH) and its antiserum.

The effect of a human placental hormone (UTPH) and UTPH-antiserum upon development of preimplantation mouse embryos was studied in vitro. UTPH at a concentration of 90 micrograms/ml had a tendency to increase the mean number of blastomeres pre embryo, and increased significantly (P less than 0.01) upon the cleavage rate. These data suggest an influence of the UT UTPH upon the early development of the embryo in mammals.