EGFR signaling promotes the identity of Drosophila follicle stem cells via maintenance of partial cell polarity

  1. Angela Castanieto
  2. Michael J Johnston
  3. Todd G Nystul  Is a corresponding author
  1. University of California, San Francisco, United States

Abstract

Epithelial stem cells divide asymmetrically, such that one daughter replenishes the stem cell pool and the other differentiates. We found that in the epithelial follicle stem cell (FSC) lineage of the Drosophila ovary, EGFR signaling functions specifically in the FSCs to promote the unique partially polarized state of the FSC, establish apical-basal polarity throughout the lineage, and promote FSC maintenance in the niche. In addition, we identified a novel connection between EGFR signaling and the cell polarity regulator, LKB1, which indicates that EGFR signals through both the Ras-Raf-MEK-Erk pathway and through the LKB1-AMPK pathway to suppress apical identity. The development of apical-basal polarity is the earliest visible difference between FSCs and their daughters, and our findings demonstrate that the EGFR-mediated regulation of apical-basal polarity is essential for the segregation of stem cell and daughter cell fates.

Article and author information

Author details

  1. Angela Castanieto

    Department of Anatomy, University of California, San Francisco, San Francisco, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Michael J Johnston

    Department of Anatomy, University of California, San Francisco, San Francisco, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Todd G Nystul

    Department of Anatomy, University of California, San Francisco, San Francisco, United States
    For correspondence
    todd.nystul@ucsf.edu
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Matthew Freeman, University of Oxford, United Kingdom

Version history

  1. Received: August 20, 2014
  2. Accepted: November 30, 2014
  3. Accepted Manuscript published: December 1, 2014 (version 1)
  4. Version of Record published: January 21, 2015 (version 2)

Copyright

© 2014, Castanieto 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.

Metrics

  • 2,895
    views
  • 443
    downloads
  • 48
    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. Angela Castanieto
  2. Michael J Johnston
  3. Todd G Nystul
(2014)
EGFR signaling promotes the identity of Drosophila follicle stem cells via maintenance of partial cell polarity
eLife 3:e04437.
https://doi.org/10.7554/eLife.04437

Share this article

https://doi.org/10.7554/eLife.04437

Further reading

    1. Cell Biology
    2. Computational and Systems Biology
    N Suhas Jagannathan, Javier Yu Peng Koh ... Lisa Tucker-Kellogg
    Research Article

    Bats have unique characteristics compared to other mammals, including increased longevity and higher resistance to cancer and infectious disease. While previous studies have analyzed the metabolic requirements for flight, it is still unclear how bat metabolism supports these unique features, and no study has integrated metabolomics, transcriptomics, and proteomics to characterize bat metabolism. In this work, we performed a multi-omics data analysis using a computational model of metabolic fluxes to identify fundamental differences in central metabolism between primary lung fibroblast cell lines from the black flying fox fruit bat (Pteropus alecto) and human. Bat cells showed higher expression levels of Complex I components of electron transport chain (ETC), but, remarkably, a lower rate of oxygen consumption. Computational modeling interpreted these results as indicating that Complex II activity may be low or reversed, similar to an ischemic state. An ischemic-like state of bats was also supported by decreased levels of central metabolites and increased ratios of succinate to fumarate in bat cells. Ischemic states tend to produce reactive oxygen species (ROS), which would be incompatible with the longevity of bats. However, bat cells had higher antioxidant reservoirs (higher total glutathione and higher ratio of NADPH to NADP) despite higher mitochondrial ROS levels. In addition, bat cells were more resistant to glucose deprivation and had increased resistance to ferroptosis, one of the characteristics of which is oxidative stress. Thus, our studies revealed distinct differences in the ETC regulation and metabolic stress responses between human and bat cells.

    1. Cell Biology
    2. Developmental Biology
    Filip Knop, Apolena Zounarova ... Marie Macůrková
    Research Article

    During Caenorhabditis elegans development, multiple cells migrate long distances or extend processes to reach their final position and/or attain proper shape. The Wnt signalling pathway stands out as one of the major coordinators of cell migration or cell outgrowth along the anterior-posterior body axis. The outcome of Wnt signalling is fine-tuned by various mechanisms including endocytosis. In this study, we show that SEL-5, the C. elegans orthologue of mammalian AP2-associated kinase AAK1, acts together with the retromer complex as a positive regulator of EGL-20/Wnt signalling during the migration of QL neuroblast daughter cells. At the same time, SEL-5 in cooperation with the retromer complex is also required during excretory canal cell outgrowth. Importantly, SEL-5 kinase activity is not required for its role in neuronal migration or excretory cell outgrowth, and neither of these processes is dependent on DPY-23/AP2M1 phosphorylation. We further establish that the Wnt proteins CWN-1 and CWN-2 together with the Frizzled receptor CFZ-2 positively regulate excretory cell outgrowth, while LIN-44/Wnt and LIN-17/Frizzled together generate a stop signal inhibiting its extension.