HesC expression represses:
HesC is global transcriptional repressor containing basic helix-loop-helix Orange domain expressed ubiquitously early in sea urchin. It binds E-boxes in promoters of micromere-specific genes including Delta ligand and skeletogenic transcription factors alx1, ets1, tbr, dri. Repression keeps Delta silent outside micromeres. In micromeres, Pmar1 represses hesC gene, derepressing targets and allowing Delta-Notch signaling. Therefore HesC expression represses Delta expression, ensuring spatially restricted signaling. Overexpression of HesC eliminates Delta and skeleton, while HesC morpholino knock
Ref: Davidson Lab, Sea Urchin GRN: HesC represses Delta expression non-micromere lineages double-negative gate.
