Abstract
Chromatin states provide the basis of epigenetic gene regulation, and chromatin reconstitution after DNA replication is the foundation for epigenetic inheritance. However, mechanism underlying chromatin reconstitution is still poorly understood. We have analyzed an Arabidopsis nuclear factor BRU1, which has been suggested to have a role for chromatin reconstitution after DNA replication and repair. Previous study showed that loss of BRU1 function caused heterochromatin instability and constitutive DNA damage response. In this study, we show that bru1 also perturbs epigenetic regulation of Polycomb target genes, such as STM and FUS3. Microarray analysis also reveals that up-regulated genes in bru1 often associated with trimethylation on histone H3K27. These results suggest that BRU1 ensures different types of epigenetic gene regulation. More surprisingly, a large portion of up-regulated genes in bru1 makes clusters in the euchromatic regions. The clusters ranged from 174 to 499 kb in size, and contained 37 to 110 genes, most of which are not associated with previously characterized epigenetic marks. Further analysis of the clusters will be presented.
