A Facilitated Diffusion Mechanism Establishes the Drosophila Dorsal Gradient Institutional Repository Document uri icon


  • SummaryThe transcription factor NF-B plays an important role in the immune system as an apoptotic and inflammatory factor. In theDrosophila melanogasterembryo, a homolog of NF-B called Dorsal (dl) patterns the dorsal-ventral (DV) axis in a concentration-dependent manner. During early development, dl is sequestered outside the nucleus by Cactus (Cact), homologous to IB. Toll signaling at the ventral midline breaks the dl/Cact complex, allowing dl to enter the nucleus where it transcribes target genes. Here we show that dl accumulates on the ventral side of the embryo over the last 5 cleavage cycles and that this accumulation is the result of facilitated diffusion of dl/Cact complex. We speculate that the predominant role for Cact in DV axis specification is to shuttle dl towards the ventral midline. Given that this mechanism has been found in other, independent systems, we suggest it may be more prevalent than previously thought.

altmetric score

  • 8.934

author list (cited authors)

  • Carrell, S. N., OConnell, M. D., Allen, A. E., Smith, S. M., & Reeves, G. T.

citation count

  • 4

complete list of authors

  • Carrell, Sophia N||O’Connell, Michael D||Allen, Amy E||Smith, Stephanie M||Reeves, Gregory T

Book Title

  • bioRxiv

publication date

  • June 2016