The effect of nuclear structural proteins on chromatin dynamics - measured by advanced live imaging methods

  Anat Vivante  ,  Irena Bronshtein  ,  Yuval Garini  
Physics Department & Nanotechnology Institute, Bar Ilan University

In eukaryotic cells, tens of thousands of genes are packed in a small volume of the nucleus. The genome is organized in chromosomes, which occupy specific volumes referred to as chromosome territories. This organization is maintained, even though there are no sub-compartments in the nucleus.

The organization of the genome is crucial for cellular functions such as gene regulation. The nuclear structure is strongly related to the dynamic properties. Hence, the dynamics of the nucleus content is fundamental for understanding its appropriate function. Understanding the mechanisms that are responsible for maintaining chromosomes within their territories and the role of specific proteins is extremely important.

We use live imaging methods to characterize the dynamic properties of the chromatin and its organization in living cells. More specifically, we use single particle tracking of different genomic regions, and implement Continuous Photobleaching (CP) measurements which provide crucial information on the mobility and binding properties of the proteins.

Through these methods, we analyze the effect of specific nuclear proteins on chromatin dynamics. Finally, we suggest a model of chromatin organization and develop a new type of diagram for mapping and analyzing the regulating networks of chromatin organization.