The proneural wave in the Drosophila optic lobe is driven by an excitable reaction-diffusion mechanism

Elife. 2019 Feb 22:8:e40919. doi: 10.7554/eLife.40919.


In living organisms, self-organised waves of signalling activity propagate spatiotemporal information within tissues. During the development of the largest component of the visual processing centre of the Drosophila brain, a travelling wave of proneural gene expression initiates neurogenesis in the larval optic lobe primordium and drives the sequential transition of neuroepithelial cells into neuroblasts. Here, we propose that this 'proneural wave' is driven by an excitable reaction-diffusion system involving epidermal growth factor receptor (EGFR) signalling interacting with the proneural gene l'sc. Within this framework, a propagating transition zone emerges from molecular feedback and diffusion. Ectopic activation of EGFR signalling in clones within the neuroepithelium demonstrates that a transition wave can be excited anywhere in the tissue by inducing signalling activity, consistent with a key prediction of the model. Our model illuminates the physical and molecular underpinnings of proneural wave progression and suggests a generic mechanism for regulating the sequential differentiation of tissues.

Keywords: D. melanogaster; developmental biology; optic lobe; physics of living systems; proneural wave; reaction-diffusion system; sequential patterning.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation*
  • Drosophila / embryology*
  • Drosophila Proteins / metabolism
  • ErbB Receptors / metabolism
  • Gene Expression Regulation, Developmental*
  • Neuroepithelial Cells / physiology*
  • Neurons / physiology*
  • Optic Lobe, Nonmammalian / embryology*
  • Receptors, Invertebrate Peptide / metabolism
  • Signal Transduction


  • Drosophila Proteins
  • Receptors, Invertebrate Peptide
  • Egfr protein, Drosophila
  • ErbB Receptors