Biological process

The global programming of epigenetic modifications in the female pronucleus of the newly fertilized zygote. The maternal genome is protected from global DNA demethylation before the first division of the zygote, and instead undergoes passive, replication-dependent demethylation during early embryogenesis, arising from inhibition of the DNA maintenance methyltransferase Dnmt1.

maintenance of DNA methylation at imprinted genes