Epigenetics – University of Copenhagen


Cells carry information handed down from their ancestors and are able to pass on information to their descendants. In many cases this ``memory" is epigenetic -- not stored in the DNA sequence -- allowing cells with identical DNA to maintain distinct properties.

Epigenetic cell memory implies alternative states that are stable over time and are inherited through cell division. Mechanism for epigenetic cell memory invokes positive feedback loops, either on genes with mutual repression or, for eukaryotes, through recruited modifications of DNA bound nucleosomes.

We explore the rules for this feedback, through a combined experimental (With Genevive Thon) and theoretical modeling, with aim to determine how stable bistability can be combined with locality for the spreading of the epigenetic states.

Another epigenetic mark is methylation respectively demethylation of CpG islands in mammals. When relatively short segment of DNA with high density of CpG sites are positioned close to a promoter, they regulate the activity of this promoter. We explore how such systems can be actively maintained, assuming that they themselves contribute to the feedback that maintain them persistently in a either methylated or a unmethylated state.