During these processes, germ cell genomes merge and give rise to the zygotic genome.

Methylation loss is associated with zygotic genome activation and at gene bodies is also linked to increased transcriptional noise in early development.

Understanding factors that regulate zygotic genome activation (ZGA) is critical for determining how cells are reprogrammed to become totipotent or pluripotent.

Early human embryogenesis relies on maternal gene products accumulated during oocyte growth and maturation, until around day-3 post-fertilization when human zygotic genome activation occurs.