EXPRESSION OF TRANSCRIPTION REGULATING GENES IN HUMAN PREIMPLANTATIONEMBRYOS

Utilizing a sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) assay system, the time course of mRNA expression of two trans cription regulators, OCT4 and OCT6, was assessed in individual preimpl antation human embryos, Examination of ova with three pronuclei and 1- cell through blastocyst stage embryos revealed that OCT4 mRNA was cont inuously expressed between the time of fertilization and 10+ cell stag es, whereas OCT6 mRNA expression was not observed until the 10+ cell s tage. The difference in the time of expression of OCT4 mRNA and OCT6 m RNA indicates that the two genes play differential roles in human embr yogenesis, Nucleotide sequence homology for OCT4 and OCT6 among mammal ian organisms supports the concept that genetic elements determining d evelopmental events during embryogenesis are conserved in evolution.