During development and cellular differentiation, cells acquire specific fates by regulating spatially and temporally the expression of certain groups of genes. This correlates with drastic changes in the 3D organization of the genome. A recent discovery from the Gasser lab has demonstrated that in differentiated cells of C. elegans, tissue-specific promoters relocate inward the 3D nuclear space when activated, and maintain this subnuclear position in a tissue-specific manner into adulthood. Another interesting finding is the relocation of heat-shock promoters toward the nuclear periphery after their induction. Altogether, the data strongly suggests a link between the subnuclear relocation of specific promoters and cellular processes.However, the exact purpose of these chromatin movements is unclear and so is the underlying mechanism, including the responsible components. Therefore, this project aims to understand the mechanism and function of the subnuclear relocation of promoters during development, and following stress induction in C. elegans. This proposal will focus first on the identification of molecular and genetic elements that may be involved in this mechanism. Second, we want to understand how the candidate components we will identify effect the subnuclear promoters' relocation, and understand for the first time the relevance of this kind of chromatin reorganization. We combine genetic manipulations, advanced biochemical methods that we will need to develop and quantitative live imaging approaches to address these questions.The work is proposed to be carried out under supervision of Prof. Susan Gasser, at the FMI institute which offers state-of-the-art facilities and provides excellent multi-disciplinary training and collaboration opportunities, thus providing the ideal environment for a successful postdoctoral stay. This postdoc experience will mean switching fields and countries which will play an essential role in my professional growth.