Peer review process
Not revised: This Reviewed Preprint includes the authors’ original preprint (without revision), an eLife assessment, and public reviews.
Read more about eLife’s peer review process.Editors
- Reviewing EditorEsteban BeckwithUniversidad de Buenos Aires - CONICET, Buenos Aires, Argentina
- Senior EditorK VijayRaghavanNational Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
Reviewer #1 (Public Review):
Summary:
The mechanisms of how axonal projections find their correct target requires the interplay of signalling pathways, and cell adhesion that act over short and long distances. The current study aims to use the small ventral lateral clock neurons (s-LNvs) of the Drosophila clock circuit as a model to study axon projections. These neurons are born during embryonic stages and are part of the core of the clock circuit in the larval brain. Moreover, these neurons are maintained through metamorphosis and become part of the adult clock circuit. The authors use the axon length by means of anti-Pdf antibody or Pdf>GFP as a read-out for the axonal length. Using ablation of the MB- the overall target region of the s-LNvs, the authors find defects in the projections. Next, by using Dscam mutants or knock-down they observe defects in the projections. Manipulations by the DNs - another group of clock neurons- can induce defects in the s-LNvs axonal form, suggesting an active role of these neurons in the morphology of the s-LNvs.
Strengths:
The use of Drosophila genetics and a specific neural type allows targeted manipulations with high precision.
Proposing a new model for a small group of neurons for axonal projections allows us to explore the mechanism with high precision.
Weaknesses:
It is unclear how far the proposed model can be seen as developmental.
The study of changes in fully differentiated and functioning neurons may affect the interpretation of the findings.
Reviewer #2 (Public Review):
Summary:
The paper from Li et al shows a mechanism by which axons can change direction during development. They use the sLNv neurons as a model. They find that the appearance of a new group of neurons (DNs) during post-embryonic proliferation secretes netrins and repels horizontally towards the midline, the axonal tip of the LNvs.
Strengths:
The experiments are well done and the results are conclusive.
Weaknesses:
The novelty of the study is overstated, and the background is understated. Both things need to be revised.
