Extrinsic Activin signaling cooperates with an intrinsic temporal program to increase mushroom body neuronal diversity

  1. Anthony M Rossi  Is a corresponding author
  2. Claude Desplan  Is a corresponding author
  1. New York University, United States

Abstract

Temporal patterning of neural progenitors leads to the sequential production of diverse neuronal types. To better understand how extrinsic cues interact with intrinsic temporal programs to contribute to temporal patterning, we studied the Drosophila mushroom body neural progenitors (neuroblasts). Each of these four neuroblasts divides ~250 times to sequentially produce only three main neuronal types over the course of ~9 days of development: g, followed by α'β', and finally αβ neurons. The intrinsic temporal clock is composed of two RNA-binding proteins, IGF-II mRNA binding protein (Imp) and Syncrip (Syp), that are expressed in opposing temporal gradients. Activin signaling affects the production of α'β' neurons but whether and how this extrinsic cue interacts with the intrinsic temporal program was not known. We show that the Activin ligand Myoglianin produced from glia downregulates the levels of the intrinsic temporal factor Imp in mushroom body neuroblasts. In neuroblasts mutant for the Activin signaling receptor baboon, Imp levels are higher than normal during the α'β' temporal window, leading to the specific loss of the α'β' neurons. The intrinsic temporal clock still progresses but with a delay, skipping the α'β' window without affecting the total number of neurons produced: The number of g neurons likely increases, α'β' disappear, and the number of αβ neurons decreases. Our results illustrate that an extrinsic cue modifies an intrinsic temporal program to increase neuronal diversity.

Data availability

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

The following previously published data sets were used

Article and author information

Author details

  1. Anthony M Rossi

    Biology, New York University, New York, United States
    For correspondence
    amr808@nyu.edu
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9345-7939
  2. Claude Desplan

    Center for Developmental Genetics, Department of Biology, New York University, New York, United States
    For correspondence
    cd38@nyu.edu
    Competing interests
    Claude Desplan, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6914-1413

Funding

National Eye Institute (R01 EY017916)

  • Claude Desplan

National Institute of Neurological Disorders and Stroke (R21 NS095288)

  • Claude Desplan

National Institutes of Health (T32 HD007520)

  • Anthony M Rossi

New York University (GSAS MacCracken Program)

  • Anthony M Rossi

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

Reviewing Editor

  1. Chris Q Doe, Howard Hughes Medical Institute, University of Oregon, United States

Version history

  1. Received: May 14, 2020
  2. Accepted: July 3, 2020
  3. Accepted Manuscript published: July 6, 2020 (version 1)
  4. Version of Record published: July 16, 2020 (version 2)

Copyright

© 2020, Rossi & Desplan

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.

Metrics

  • 2,085
    views
  • 332
    downloads
  • 22
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Anthony M Rossi
  2. Claude Desplan
(2020)
Extrinsic Activin signaling cooperates with an intrinsic temporal program to increase mushroom body neuronal diversity
eLife 9:e58880.
https://doi.org/10.7554/eLife.58880

Share this article

https://doi.org/10.7554/eLife.58880

Further reading

    1. Computational and Systems Biology
    2. Developmental Biology
    Gang Xue, Xiaoyi Zhang ... Zhiyuan Li
    Research Article

    Organisms utilize gene regulatory networks (GRN) to make fate decisions, but the regulatory mechanisms of transcription factors (TF) in GRNs are exceedingly intricate. A longstanding question in this field is how these tangled interactions synergistically contribute to decision-making procedures. To comprehensively understand the role of regulatory logic in cell fate decisions, we constructed a logic-incorporated GRN model and examined its behavior under two distinct driving forces (noise-driven and signal-driven). Under the noise-driven mode, we distilled the relationship among fate bias, regulatory logic, and noise profile. Under the signal-driven mode, we bridged regulatory logic and progression-accuracy trade-off, and uncovered distinctive trajectories of reprogramming influenced by logic motifs. In differentiation, we characterized a special logic-dependent priming stage by the solution landscape. Finally, we applied our findings to decipher three biological instances: hematopoiesis, embryogenesis, and trans-differentiation. Orthogonal to the classical analysis of expression profile, we harnessed noise patterns to construct the GRN corresponding to fate transition. Our work presents a generalizable framework for top-down fate-decision studies and a practical approach to the taxonomy of cell fate decisions.

    1. Developmental Biology
    2. Evolutionary Biology
    Zhuqing Wang, Yue Wang ... Wei Yan
    Research Article

    Despite rapid evolution across eutherian mammals, the X-linked MIR-506 family miRNAs are located in a region flanked by two highly conserved protein-coding genes (SLITRK2 and FMR1) on the X chromosome. Intriguingly, these miRNAs are predominantly expressed in the testis, suggesting a potential role in spermatogenesis and male fertility. Here, we report that the X-linked MIR-506 family miRNAs were derived from the MER91C DNA transposons. Selective inactivation of individual miRNAs or clusters caused no discernible defects, but simultaneous ablation of five clusters containing 19 members of the MIR-506 family led to reduced male fertility in mice. Despite normal sperm counts, motility, and morphology, the KO sperm were less competitive than wild-type sperm when subjected to a polyandrous mating scheme. Transcriptomic and bioinformatic analyses revealed that these X-linked MIR-506 family miRNAs, in addition to targeting a set of conserved genes, have more targets that are critical for spermatogenesis and embryonic development during evolution. Our data suggest that the MIR-506 family miRNAs function to enhance sperm competitiveness and reproductive fitness of the male by finetuning gene expression during spermatogenesis.