RNA Pol II photoregulation
Plant cells display outstanding capacities to reprogram genome expression in response to developmental and environmental signals, yet we ignore whether modulation of transcription activity involves specific spatial redeployments of genes and transcription machinery. Having uncovered that light perception triggers higher-order changes in chromatin organization, and a global increase of the transcriptional regime during Arabidopsis cotyledon photomorphogenesis (Bourbousse, Mestiri et al, 2015), this collaborative project aims at exploring the links between genome topology and transcription patterns.
Arabidopsis cotyledon chromatin sub-domains.
Image courtesy of Célia Baroux
In collaboration with the Baroux (UZH) and Benhamed (IPS2, Orsay) labs, the project combines super-resolution microscopy and genome profiling of transcription topology. This interdisciplinary approach enables to explore the dynamic changes of active RNA Pol II sub-nuclear patterns during Arabidopsis cotyledon photomorphogenesis.
Our first observations unveiled that light induces the formation of transcription clusters near the nuclear periphery. This pattern contrasts with situations in yeast and mammals where gene activation is more often accompanied by relocation from the nuclear periphery, enriched in heterochromatin, to the nuclear interior.
In future studies, we will identify which genes form such super-clusters and describe their sub-nuclear dynamics in situ with the long-term objective to decipher their potential regulatory role.
Collaborative project coordinated by Fredy Barneche & Célia Baroux (UZH), funded by Velux Stiftung and the ANR ChromatinPhotoDynamics grant
