show Abstracthide AbstractSensing and responding to light provides organisms an adaptive advantage, in part by altering gene expression. The complement of light-activated genes in model organisms is largely known, and some of the mechanisms by which proteins modulate the light response are likewise well defined. However, how light alters post translation modifications to chromatin and how changes in chromatin facilitates and/or inhibit changes in gene expression has not been examined in depth. Nor is know how specific chromatin-modifiers assist in modulating the light response or the extent of the defects in strains lacking certain chromatin modifications. Using a combination of RNA-seq and ChIP-seq we examines H3K4 methylation and H3K9 methylation and found paradigm changing properties beyond the consensus that H3K4me3 is a solely a mark for activation and H3K9me3 marks silent heterochromatin domains. Overall design: Samples consist of different strains, harvest times, and antibodies.