Physical biology of chromatin: understanding the functional role of 3D chromosome folding using polymer physics
Daniel Jost (Université Grenoble Alpes)
Cellular differentiation occurs during the development of multicellular organisms and leads to the formation of many different tissues where gene expression is modulated without modification of the genetic information. These modulations are in part encoded by chromatin-associated proteins or biochemical tags that are set down at the chromatin level directly on DNA or on histone tails. These markers are directly or indirectly involved in the local organization and structure of the chromatin fiber, and therefore may modulate the accessibility of DNA to transcription factors or enzymatic complexes, playing a fundamental role in the transcriptional regulation of gene expression. Propagation, maintenance and inheritance of these epigenetic marks are crucial mechanisms in development, phenotype stabilization and disease. Experimental evidence have shown that the pattern of chromatin markers along chromosomes is strongly correlated with the 3D chromatin organization inside the nucleus. This suggests a coupling between epigenomic information and large-scale chromatin structure. Here, I will discuss our recent works using polymer physics and numerical simulations trying to understand the basic principles behind such coupling and and to propose possible functional roles for the 3D organization of chromosomes.