Resetting histone modifications during human parental-to-zygotic transition

Epigenetics of human embryonic development Substantial epigenetic reprogramming occurs in mammalian early development. Xia et al. investigated the reprogramming dynamics of three key histone modifications in human early embryonic development. The reprogramming in humans is highly species-specific and different than that in mice. A globally permissive chromatin state connects parental and zygotic epigenomes during maternal-to-zygotic transition. Inner-cell mass-specific, but not trophectoderm-specific, genes are asymmetrically patterned by a histone mark during early lineage segregation. Science , this issue p. 353