What an epigenome remembers.

During mammalian development, maintenance of cell fate through mitotic divisions require faithful replication not only of the DNA but also of a particular epigenetic state. Germline cells have the capacity of erasing this epigenetic memory at crucial times during development, thereby resetting their epigenome. Certain marks, however, appear to escape this reprogramming, which allows their transmission to the offspring and potentially guarantees transgenerational epigenetic inheritance. Here we discuss the molecular requirements for faithful transmission of epigenetic information and our current knowledge about the transmission of epigenetic information through generations.