Régulation épigénétique de l’organisation et de la stabilité du centromère chez les mammifères – ECenS

ABSTRACT 'Epigenetic regulation of centromere organization and stability in mammals' The centromere is a chromosomal region which plays an essential role in chromosome segregation. Importantly, the specification of centromere identity is not governed by a DNA sequence and rather depends on features defined by chromatin organization. Understanding how the stable inheritance of this organization is ensured throughout multiple cellular divisions is a major unresolved paradigm in Epigenetics. Within centromeres, two domains, called pericentric and centric, show distinct chromatin properties. Importantly, both domains are essential for centromere function and pertubing either of these two domains lead to defects in chromosome segregation that can give rise to aneuploidy. Our project aims to address the 'EcenS'-tial issue of the 'Epigenetic regulation of Centromere organization and Stability in mammals' by gaining novel insights into the fundamental mechanistic aspects that govern the formation, maintenance and dynamics of the centromere in mammals. To address this issue we propose to carry out a comprehensive analysis of the dynamics of both the centric and pericentric chromatin domains. Our main objectives will be : (1) to identify how key parameters contribute to centromere organization (centric & pericentric) both for assembly and maintenance, (2) to understand how these components and centromeric organization behave in terms of their dynamics during the cell cycle and investigate the interrelationships between centric and pericentric domains, (3) to analyze how DNA damage affects centromere organization and stability. We will use a series of molecular and cellular approaches involving biochemical/proteomic analysis, live cell imaging incorporating the new SNAP-tag technology as well as novel methodologies such as DNA combing, chromatin fibres combined with functional assays during the cell cycle. New models will be developped for studies during development and in the context of cancer. We thus hope to identify new actors and decipher the mechanisms involved in the regulation of centromeric chromatin organization and function. These findings should not only advance our basic knowledge on centromere function but also shed light on a central paradigm of epigenetics with possible implications for cancer biology.