Disentangling metaphase chromosome organisation one chromosome at a time

ongoing

Chromosomes assume their most compact state during metaphase just before they are separated. In this process of cell division the chromosomes experience high forces and genomic defects can occur then. Many techniques have built considerable understanding of metaphase chromosome structure and a multitude of models have been put forward how cells organize their chromosomes during metaphase. Yet, given the complexity of the process and limitations of the methods to study them, it is far from being fully understood. The breakthrough opportunity in this regard is the development of tools that allow real-time, 3D, super-resolution imaging and manipulation of entire non-fixed metaphase chromosomes under nearphysiological conditions. Here I propose to quantitatively image the proteins that establish the architecture of metaphase chromosomes and disentangle the connection between its architecture, internal protein dynamics and mechanics at the multi-protein as well as the single-molecule level. For this project I plan to expand the combination of optical manipulation and fluorescent microscopy by introducing force-induced expansion microscopy together with advanced labeling and imaging techniques that ultimately will permit real-time, 3D, super-resolution quantitative analysis of complex (protein) structures within native non-fixed metaphase chromosomes. With this kind of instrument it becomes possible to validate and/or challenge the current models of metaphase organization as well as explore the physical properties of chromosomes but also study chromosome separation dynamics. My extensive experience handling biological systems and pushing instrumental boundaries gives me an excellent starting point to address key research questions with regards to metaphase chromosomes. In doing so I can improve our understanding of chromosome organization which is important because chromosome defects can have devastating consequences leading to for example cancer or fragile X syndrome.