R7 photoreceptor axon targeting depends on the relative levels of lost and found expression in R7 and its synaptic partners

  1. Jessica Douthit
  2. Ariel Hairston
  3. Gina Lee
  4. Carolyn Arlene Morrison
  5. Isabel Holguera
  6. Jessica E Treisman  Is a corresponding author
  1. NYU School of Medicine, United States
  2. NYU, United States

Abstract

As neural circuits form, growing processes select the correct synaptic partners through interactions between cell surface proteins. The presence of such proteins on two neuronal processes may lead to either adhesion or repulsion; however, the consequences of mismatched expression have rarely been explored. Here we show that the Drosophila CUB-LDL protein Lost and found (Loaf) is required in the UV-sensitive R7 photoreceptor for normal axon targeting only when Loaf is also present in its synaptic partners. Although targeting occurs normally in loaf mutant animals, removing loaf from photoreceptors or expressing it in their postsynaptic neurons Tm5a/b or Dm9 in a loaf mutant causes mistargeting of R7 axons. Loaf localizes primarily to intracellular vesicles including endosomes. We propose that Loaf regulates the trafficking or function of one or more cell surface proteins, and an excess of these proteins on the synaptic partners of R7 prevents the formation of stable connections.

Data availability

All data generated or analyzed during this study are included in the manuscript and supporting files.

Article and author information

Author details

  1. Jessica Douthit

    Skirball Institute/Cell Biology, NYU School of Medicine, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Ariel Hairston

    Skirball Institute/Cell Biology, NYU School of Medicine, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Gina Lee

    Skirball Institute/Cell Biology, NYU School of Medicine, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Carolyn Arlene Morrison

    Skirball Institute/Cell Biology, NYU School of Medicine, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Isabel Holguera

    Biology, NYU, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-2796-6596
  6. Jessica E Treisman

    Skirball Institute/Cell Biology, NYU School of Medicine, New York, United States
    For correspondence
    Jessica.Treisman@med.nyu.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7453-107X

Funding

National Institutes of Health (R01GM089799)

  • Jessica E Treisman

National Institutes of Health (R01NS112211)

  • Jessica E Treisman

National Institutes of Health (F31EY025568)

  • Jessica Douthit

Human Frontier Science Program ((LT000757/2017)

  • Isabel Holguera

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Carol A Mason, Columbia University, United States

Publication history

  1. Received: December 18, 2020
  2. Accepted: May 17, 2021
  3. Accepted Manuscript published: May 18, 2021 (version 1)
  4. Version of Record published: June 15, 2021 (version 2)

Copyright

© 2021, Douthit et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Jessica Douthit
  2. Ariel Hairston
  3. Gina Lee
  4. Carolyn Arlene Morrison
  5. Isabel Holguera
  6. Jessica E Treisman
(2021)
R7 photoreceptor axon targeting depends on the relative levels of lost and found expression in R7 and its synaptic partners
eLife 10:e65895.
https://doi.org/10.7554/eLife.65895
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