Abstract
Transcriptionally silent genes are associated with heterochromatic epigenetic modifications such as DNA methylation and histone H3 Lysine9 methylation. Although removal of such modifications is essential for gene de-repression, the molecular mechanisms underlying the removal of the heterochromatic modifications are still poorly understood. Using model plant Arabidopsis, we are studying regulation mechanisms of heterochromatic modifications, and trying to identify novel factors involved in this process. By taking a forward genetic approach, we demonstrated that a jumonji-domain protein IBM1 is required for negative regulation of DNA methylation and histone H3 Lysine9 methylation at transcribed genic regions. ibm1 plants exhibit various developmental abnormalities, suggesting that the H3K9 demethylation pathway is essential for regulation of gene activities during development. I will discuss the pathway and factors regulating heterochromatic modifications in genic regions.
