RT Journal Article
SR Electronic
T1 Optogenetic control of the Bicoid morphogen reveals fast and slow modes of gap gene regulation
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.10.13.464280
DO 10.1101/2021.10.13.464280
A1 Singh, Anand P.
A1 Wu, Ping
A1 Ryabichko, Sergey
A1 Raimundo, João
A1 Swan, Michael
A1 Wieschaus, Eric
A1 Gregor, Thomas
A1 Toettcher, Jared E.
YR 2021
UL http://biorxiv.org/content/early/2021/10/14/2021.10.13.464280.abstract
AB 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 quantitative regulatory dynamics from a complex genetic network in vivo. We engineer light-controlled variants of the Bicoid transcription factor and study their effects on downstream gap genes in embryos. Our results recapitulate known relationships, including rapid Bicoid-dependent expression of giant and hunchback and delayed repression of Krüppel. In contrast, we find that the posterior pattern of knirps exhibits a quick but inverted response to Bicoid perturbation, suggesting a previously unreported role for Bicoid in suppressing knirps expression. Acute modulation of transcription factor concentration while simultaneously recording output gene activity represents a powerful approach for studying how gene circuit elements are coupled to cell identification and complex body pattern formation in vivo.Competing Interest StatementThe authors have declared no competing interest.