Seminario Generale
Chromosomes as communication and memory machines
by Leonid A. Mirny (Institute for Medical Engineering and Science, and Department of Physics Massachusetts Institute of Technology,Cambridge, MA)
Tuesday Nov 11, 2025, 4:00 PM → 6:00 PM Europe/Rome
Aula Conversi (Dipartimento di Fisica-Ed. G.Marconi)

Chromosomes are long polymers of genomic DNA decorated with proteins.
We are interested in understanding how cells fold chromosomes to read, write, and process genetic and epigenetic information. Could the way chromosomes are folded carry information itself?
First, we discovered that chromosomes are folded by the ATP-dependent process of loop extrusion, where molecular motors form progressively larger loops. This collective action of nanometer-sized motors shapes micrometer-sized chromosomes. We demonstrated how this mechanism can also establish complex long-range and targeted communication between regulatory elements and genes.
Second, we found that chromosome folding plays a key role in storing "epigenetic memory," which refers to patterns of chemical marks along the genome. Although these marks are subject to loss and spreading by enzymes, when genome folding is influenced by the marks, the pattern can be preserved for hundreds of cell divisions. We also identified a parallel between this mechanism of epigenetic memory and associative memory in neural networks, suggesting that this system may be capable of performing more complex information-processing tasks.