Epigenetics and interphase chromosomes in living plants

A complete understanding of genome function and regulation will require not only information about the linear DNA sequence and associated nuclear proteins but also about how these molecular components are assembled, arranged and dynamically controlled in interphase nuclei of plant and animal cells. Current views of eukaryotic gene regulation emphasize structural and epigenetic characteristics of chromatin itself as well as the spatial disposition of chromatin domains in the three-dimensional (3D) space of the nucleus. A major challenge is to elucidate not only the 3D architecture of interphase chromatin but also to integrate this spatial information with epigenetic modifications and chromatin mobility in vivo. The purpose of the work proposed here is to study how epigenetic processes impact 3D interphase chromosome disposition, dynamics and expression in living plant cells. The experiments will be performed using the model plant Arabidopsis thaliana, for which the necessary tools are available: (1) transgenic lines with fluorescent tags at different chromosomal sites, which can be viewed in interphase nuclei of living plants; and (2) mutants impaired in various types of epigenetic gene silencing. Results from these investigations will help to integrate epigenetic modifications into a comprehensive picture of the the 3D organization and dynamic nature of interphase chromatin in living cells.

A complete understanding of genome function and regulation will require not only information about the linear DNA sequence and associated nuclear proteins but also about how these molecular components are assembled, arranged and dynamically controlled in interphase nuclei of plant and animal cells. Current views of eukaryotic gene regulation emphasize structural and epigenetic characteristics of chromatin itself as well as the spatial disposition of chromatin domains in the three-dimensional (3D) space of the nucleus. A major challenge is to elucidate not only the 3D architecture of interphase chromatin but also to integrate this spatial information with epigenetic modifications and chromatin mobility in vivo. The purpose of the work proposed here is to study how epigenetic processes impact 3D interphase chromosome disposition, dynamics and expression in living plant cells. The experiments will be performed using the model plant Arabidopsis thaliana, for which the necessary tools are available: (1) transgenic lines with fluorescent tags at different chromosomal sites, which can be viewed in interphase nuclei of living plants; and (2) mutants impaired in various types of epigenetic gene silencing. Results from these investigations will help to integrate epigenetic modifications into a comprehensive picture of the the 3D organization and dynamic nature of interphase chromatin in living cells.