Compartmentalization and Dynamics of Nuclear Functions

The tri-dimensional organization of the genome is clearly linked to its function as it varies during the cell cycle and upon differentiation in metazoan.

However, the causal relationship between nuclear organization and function remains often elusive. Budding yeast has proven to be an excellent model system for testing the functional role of higher-order chromatin organization. Extensive studies over the last two decades have revealed a dynamic yet well-defined organization of the yeast genome, which impacts on gene expression and genome stability through mechanisms that are still poorly understood (Taddei et al, 2012 ; Miné-Hattab and Taddei 2019).

Using this model system, we ask three main questions:

1- How nuclear organization affects two essential functions of the genome: gene expression and the maintenance of genome integrity?

2- What determines the spatial and temporal behavior of chromatin?

3- What is the physical nature of subnuclear compartments?

One of the prominent features of nuclear organization is the existence of subnuclear compartments that are not membrane-enclosed but yet concentrate specific factors forming microenvironment that favor or impede particular activities. Deciphering how such microenvironments are formed despite the absence of physical barrier to delimitate them, and what regulate their dynamics in relation to changes in genome activity is a key step in understanding how nuclear organization participates in nuclear function.