At any moment, the developmental state of a cell is reflected directly in chromatin structure, and the organization of this structure changes rapidly during embryogenesis in response to developmental cues. Yet, the mechanistic underpinnings of these transitions in chromatin structure, particularly in response to developmental signals, is poorly understood. My laboratory uses the Drosophila embryo as a model system to study the mechanisms that establish the chromatin architecture of pluripotent embryonic cells from an unpatterned ground state. Our goal is to understand both the molecular determinants for specification of ‘active’ versus ‘repressed’ chromatin, and also how developmental signals provide information to alter chromatin states over time. We combine the power of Drosophila genetics with genomic methods for interrogating chromatin accessibility and occupancy, in addition to developing confocal imaging approaches for quantitative assessment of chromatin state.
Current projects include measuring changes in chromatin accessibility status in the absence of all developmental patterning cues; functional studies on transcription factors such as Bicoid that are associated with chromatin modifying activities; genetic screening for mutants that disrupt the pluripotent chromatin state; and development of optical tools for direct assessment of local chromatin accessibility status in real time.