Transcription of paternal Y-linked genes in the human zygote as early as the pronucleate stage

Abstract

Summary: Global activation of the embryonic genome occurs at the 4– to 8–cell stage in human embryos and is marked by continuation of early cleavage divisions in the presence of transcriptional inhibitors. Here we demonstrate, using recerse transcripase–polymerase chin reaction (Rt–PCR), the presence of transcripts for wo paternal Y chromosomal genes,ZFYandSRYin human preimplantation embryos.ZFYtranscripts were detected as early as the pronucleate stage, 20–24 h post-inseminationIn vitroand at intermediate stages up to the blastocyst stage.SRYTranscripts were also detected at 2–cell to blastocyos observed in many mammalian species focuses attention on the role of events in six determination prior to gonad differentiation.