AP-2α and AP-2β cooperatively function in the craniofacial surface ectoderm to regulate chromatin and gene expression dynamics during facial development

  1. Eric Van Otterloo  Is a corresponding author
  2. Isaac Milanda
  3. Hamish Pike
  4. Jamie A Thompson
  5. Hong Li
  6. Kenneth L Jones
  7. Trevor Williams  Is a corresponding author
  1. University of Iowa, United States
  2. University of Colorado Anschutz Medical Campus, United States
  3. University of Oklahoma Health Sciences Center, United States

Abstract

The facial surface ectoderm is essential for normal development of the underlying cranial neural crest cell populations, providing signals that direct appropriate growth, patterning, and morphogenesis. Despite the importance of the ectoderm as a signaling center, the molecular cues and genetic programs implemented within this tissue are understudied. Here we show that removal of two members of the AP-2 transcription factor family, AP-2α and AP-2ß, within the early embryonic ectoderm of the mouse leads to major alterations in the craniofacial complex. Significantly, there are clefts in both the upper face and mandible, accompanied by fusion of the upper and lower jaws in the hinge region. Comparison of ATAC-seq and RNA-seq analyses between controls and mutants revealed significant changes in chromatin accessibility and gene expression centered on multiple AP-2 binding motifs associated with enhancer elements within these ectodermal lineages. In particular, loss of these AP-2 proteins affects both skin differentiation as well as multiple signaling pathways, most notably the WNT pathway. We also determined that the mutant clefting phenotypes that correlated with reduced WNT signaling could be rescued by Wnt1 ligand overexpression in the ectoderm. Collectively, these findings highlight a conserved ancestral function for AP-2 transcription factors in ectodermal development and signaling, and provide a framework from which to understand the gene regulatory network operating within this tissue that directs vertebrate craniofacial development.

Data availability

Sequencing data has been deposited in the Gene Expression Omnibus under accession code GSE199342.

The following data sets were generated
The following previously published data sets were used

Article and author information

Author details

  1. Eric Van Otterloo

    Iowa Institute for Oral Health Research, University of Iowa, Iowa City, United States
    For correspondence
    eric-vanotterloo@uiowa.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5958-5742
  2. Isaac Milanda

    Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Aurora, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Hamish Pike

    Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Aurora, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Jamie A Thompson

    Iowa Institute for Oral Health Research, University of Iowa, Iowa City, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Hong Li

    Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Aurora, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Kenneth L Jones

    Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahama City, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Trevor Williams

    Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Aurora, United States
    For correspondence
    trevor.williams@cuanschutz.edu
    Competing interests
    The authors declare that no competing interests exist.

Funding

National Institute of Dental and Craniofacial Research (2R01 DE12728)

  • Trevor Williams

National Institute of Dental and Craniofacial Research

  • Eric Van Otterloo

University of Iowa

  • Eric Van Otterloo

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 experiments were conducted in accordance with all applicable guidelines and regulations, following the 'Guide for the Care and Use of Laboratory Animals of the National Institutes of Health'. The animal protocol utilized was approved by the Institutional Animal Care and Use Committee of the University of Colorado - Anschutz Medical Campus (#14) and the Institutional Animal Care and Use Committee of the University of Iowa (#9012197).

Reviewing Editor

  1. Paul Trainor

Publication history

  1. Received: May 19, 2021
  2. Preprint posted: June 10, 2021 (view preprint)
  3. Accepted: March 22, 2022
  4. Accepted Manuscript published: March 25, 2022 (version 1)
  5. Version of Record published: April 25, 2022 (version 2)

Copyright

© 2022, Van Otterloo 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. Eric Van Otterloo
  2. Isaac Milanda
  3. Hamish Pike
  4. Jamie A Thompson
  5. Hong Li
  6. Kenneth L Jones
  7. Trevor Williams
(2022)
AP-2α and AP-2β cooperatively function in the craniofacial surface ectoderm to regulate chromatin and gene expression dynamics during facial development
eLife 11:e70511.
https://doi.org/10.7554/eLife.70511

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