Topological constraints and chromosome organization in eukaryotes: a physical point of view

New experimental tools capable of probing the three-dimensional organization of eukaryotic genomes with an unprecedented level of detail have been developed in the last few years. In the quest for a quantitative understanding of experimental results, several polymer models for chromatin organization were introduced and critically evaluated. In the present article, I give a brief introduction to the physical basis of chromosome organization, and recall the experimental evidence in favour of the importance of topological constraints for the description of chromosome conformations in eukaryotes.