M. Nollmann // A key output of the NIH-Common Fund 4D Nucleome (4DN) project 1,2 is the open publication of datasets related to the structure of the human cell nucleus and the genome. Recent years have seen a rapid expansion of multiplexed Fluorescence In Situ Hybridization (FISH) or FISH-omics methods, which quantify the spatial organization of chromatin in single cells, sometimes together with RNA and protein measurements, and provide an expanded understanding of how 3D higher-order chromosome structure relates to transcriptional activity and cell development in both health and disease.

Hossein Salari, Daniel Jost // Chromosomes are complex biopolymers folded into dynamic loops via a loop extrusion process and may experience various mechanical forces in vivo. We develop a force-dependent model of chromatin loop extrusion and investigate its mechanical consequences on chromosome organization using simulations and analytical theory. We show that loop extrusion alters the force–extension behavior of DNA in a non-monotonic manner: extrusion stiffens the chain at low forces but softens it at intermediate and high forces.

Geneviève Almouzni