DNA methylation plays a key role in mammalian development. Methylation patterns are laid down before an embryo develops. Reprogramming errors during development can cause diseases such as Beckwith-Wiedemann-, Angelman- and Prader-Willi- syndromes and cancer. Jörn’s group wants to understand how DNA methylation patterns arise and persist. So they’re looking at epigenetic mechanisms that control imprinting and the consequences of ART such as IVF and ICSI on genomic imprints. In addition, Jörn and his team are creating epigenomic reference maps for certain human chromosomes.