Abstract

Mesenchymal condensation is a critical step in organogenesis, yet the underlying molecular and cellular mechanisms remain poorly understood. The hair follicle dermal condensate is the precursor to the permanent mesenchymal unit of the hair follicle, the dermal papilla, which regulates hair cycling throughout life and bears hair inductive potential. Dermal condensate morphogenesis depends on epithelial Fibroblast Growth Factor 20 (Fgf20). Here, we combine mouse models with 3D and 4D microscopy to demonstrate that dermal condensates form de novo and via directional migration. We identify cell cycle exit and cell shape changes as early hallmarks of dermal condensate morphogenesis and find that Fgf20 primes these cellular behaviors and enhances cell motility and condensation. RNAseq profiling of immediate Fgf20 targets revealed induction of a subset of dermal condensate marker genes. Collectively, these data indicate that dermal condensation occurs via directed cell movement and that Fgf20 orchestrates the early cellular and molecular events.

Data availability

Sequencing data have been deposited in GEO under accession codes GSE110459. All data analyzed for this study are included in the manuscript and supporting files. Source data files have been provided where appropriate.

The following data sets were generated

Article and author information

Author details

  1. Leah C Biggs

    Developmental Biology Program, University of Helsinki, Helsinki, Finland
    For correspondence
    leah.biggs@helsinki.fi
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4990-8664
  2. Otto J.M. Mäkelä

    Developmental Biology Program, University of Helsinki, Helsinki, Finland
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6852-9814
  3. Satu-Marja Myllymäki

    Developmental Biology Program, University of Helsinki, Helsinki, Finland
    Competing interests
    The authors declare that no competing interests exist.
  4. Rishi Das Roy

    Developmental Biology Program, University of Helsinki, Helsinki, Finland
    Competing interests
    The authors declare that no competing interests exist.
  5. Katja Närhi

    Developmental Biology Program, University of Helsinki, Helsinki, Finland
    Competing interests
    The authors declare that no competing interests exist.
  6. Johanna Pispa

    Developmental Biology Program, University of Helsinki, Helsinki, Finland
    Competing interests
    The authors declare that no competing interests exist.
  7. Tuija Mustonen

    Developmental Biology Program, University of Helsinki, Helsinki, Finland
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2429-5064
  8. Marja L Mikkola

    Developmental Biology Program, University of Helsinki, Helsinki, Finland
    For correspondence
    marja.mikkola@helsinki.fi
    Competing interests
    The authors declare that no competing interests exist.

Funding

Sigrid Juséliuksen Säätiö

  • Marja L Mikkola

Jane and Aatos Erkko Foundation

  • Marja L Mikkola

Doctoral Program in Integrative Life Science of the University of Helsinki

  • Otto J.M. Mäkelä

Academy of Finland (268798)

  • Marja L Mikkola

Academy of Finland (307421)

  • Marja L Mikkola

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

Ethics

Animal experimentation: All mouse studies were approved and carried out in accordance with the guidelines of the Finnish national animal experimentation board under licenses KEK16-021 and ESAV/2363/04.10.07/2017.

Reviewing Editor

  1. Valerie Horsley, Yale University, United States

Version history

  1. Received: March 7, 2018
  2. Accepted: July 30, 2018
  3. Accepted Manuscript published: July 31, 2018 (version 1)
  4. Version of Record published: August 23, 2018 (version 2)

Copyright

© 2018, Biggs 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. Leah C Biggs
  2. Otto J.M. Mäkelä
  3. Satu-Marja Myllymäki
  4. Rishi Das Roy
  5. Katja Närhi
  6. Johanna Pispa
  7. Tuija Mustonen
  8. Marja L Mikkola
(2018)
Hair follicle dermal condensation forms via Fgf20 primed cell cycle exit, cell motility, and aggregation
eLife 7:e36468.
https://doi.org/10.7554/eLife.36468

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