@article{4395,
  keywords = {Trans-Activators, Drosophila Proteins, Gene Expression Regulation, Developmental, Optogenetics, Homeodomain Proteins},
  author = {Anand Singh and Ping Wu and Sergey Ryabichko and Jo{\~a}o Raimundo and Michael Swan and Eric Wieschaus and Thomas Gregor and Jared Toettcher},
  title = {Optogenetic control of the Bicoid morphogen reveals fast and slow modes of gap gene regulation.},
  abstract = { <p>Developmental patterning networks are regulated by multiple inputs and feedback connections that rapidly reshape gene expression, limiting the information that can be gained solely from slow genetic perturbations. Here we show that fast optogenetic stimuli, real-time transcriptional reporters, and a simplified genetic background can be combined to reveal the kinetics of gene expression downstream of a developmental transcription factor in~vivo. We engineer light-controlled versions of the Bicoid transcription factor and study their effects on downstream gap genes in embryos. Our results recapitulate known relationships, including rapid Bicoid-dependent transcription of giant and hunchback and delayed repression of Kr{\"u}ppel. In addition, we find that the posterior pattern of knirps exhibits a quick but inverted response to Bicoid perturbation, suggesting a noncanonical role for Bicoid in directly suppressing knirps transcription. Acute modulation of transcription factor concentration while recording output gene activity represents a powerful approach for studying developmental gene networks in~vivo.</p> },
  year = {2022},
  journal = {Cell Rep},
  volume = {38},
  pages = {110543},
  month = {2022 Mar 22},
  issn = {2211-1247},
  doi = {10.1016/j.celrep.2022.110543},
  language = {eng},
}