Chromatin polymorphism and dynamics’

 Through its local heterogeneities and transient structural changes resulting from chemical modifications and physical constraints imposed by numerous actors in vivo, chromatin plays a critical role in the regulation of DNA metabolism processes. To identify the main features of nucleosome dynamics and polymorphism, we use a combination of molecular biology (chromatin reconstitution and analysis by gel electrophoresis and sedimentation analysis), biophysics (electron and atomic force microscopies, magnetic tweezers) and theoretical (physical modelling, sequence analysis) approaches. Experiments and models aimed at deciphering some key features of chromatin dynamics and topology will be presented.This will give us the opportunity to show how DNA sequence may influence both nucleosome positioning and topology and how these local properties may have repercussions on chromatin conformation and response to physiological constraints.