A program of successive gene expression in mammalian one-cell embryos during first cell cycle

In mammal, by fertilization, sperm and oocyte unite to produce a totipotent one-cell embryo.  The gamete-derived genomes are known to be transcriptionally silent until the onset of embryonic genome activation (EGA).  EGA is critical for development and establishment of totipotency, yet its timing and profile remain elusive in both human and mouse.  We here employed high resolution single cell RNA sequence on precisely synchronized mouse embryos and human healthy binuclear (2PN) one-cell embryos. Results showed that programmed succession of gene expression during the first cell cycle (one- to two cell embryo development) and its upstream regulators.  Furthermore, together with live-imaging analyses and immunocytochemistry, multiple aspects of results indicated a unique, non-canonical, features of the first embryonic cell division.