One of the interests of my group is to dissect the functional modifications of the chromatin during the process of somatic cell reprogramming to pluripotency. By using quantitative super-resolution nanoscopy, we identified a novel chromatin fiber assembly and the relation among the decoded structure and naïve pluripotency. We showed that nucleosomes arrange in groups of various sizes along the chromatin fiber, which we named ‘nucleosome clutches’ (in analogy with clutches of eggs). Clutches are interspersed with nucleosome-free regions. We are currently inspecting the 3D-structure and dynamics of the chromatin fiber as well as its looping using super resolution microscopy and modeling approaches. We are investing how the spatial organization of the chromatin fibers functionally change in stem and somatic cells.