1. Developmental Biology
  2. Evolutionary Biology
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Divergent mechanisms regulate conserved cardiopharyngeal development and gene expression in distantly related ascidians

  1. Alberto Stolfi
  2. Elijah K Lowe
  3. Claudia Racioppi
  4. Filomena Ristoratore
  5. C Titus Brown
  6. Billie J Swalla
  7. Lionel Christiaen  Is a corresponding author
  1. New York University, United States
  2. Michigan State University, United States
  3. Stazione Zoologica Anton Dohrn, Italy
  4. University of Washington, United States
Research Article
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Cite this article as: eLife 2014;3:e03728 doi: 10.7554/eLife.03728

Abstract

Ascidians present a striking dichotomy between conserved phenotypes and divergent genomes: embryonic cell lineages and gene expression patterns are conserved between distantly related species. Much research has focused on Ciona or Halocynthia spp. but development in other ascidians remains poorly characterized. Here we surveyed the multipotent myogenic B7.5 lineage in Molgula spp. Comparisons to the homologous lineage in Ciona revealed identical cell division and fate specification events that result in segregation of larval, cardiac, and pharyngeal muscle progenitors. Moreover, the expression patterns of key regulators are conserved, but cross-species transgenic assays uncovered incompatibility, or "unintelligibility", of orthologous cis-regulatory sequences between Molgula and Ciona. These sequences drive identical expression patterns that are not recapitulated in cross-species assays. We show that this unintelligibility is likely due to changes in both cis- and trans-actingelements, hinting at widespread and frequent turnover of regulatory mechanisms underlying otherwise conserved aspects of ascidian embryogenesis.

Article and author information

Author details

  1. Alberto Stolfi

    New York University, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Elijah K Lowe

    Michigan State University, East Lansing, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Claudia Racioppi

    Stazione Zoologica Anton Dohrn, Napoli, Italy
    Competing interests
    The authors declare that no competing interests exist.
  4. Filomena Ristoratore

    Stazione Zoologica Anton Dohrn, Napoli, Italy
    Competing interests
    The authors declare that no competing interests exist.
  5. C Titus Brown

    Michigan State University, East Lansing, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Billie J Swalla

    University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Lionel Christiaen

    New York University, New York, United States
    For correspondence
    lc121@nyu.edu
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Margaret Buckingham, Institut Pasteur, France

Publication history

  1. Received: June 18, 2014
  2. Accepted: September 5, 2014
  3. Accepted Manuscript published: September 10, 2014 (version 1)
  4. Version of Record published: September 30, 2014 (version 2)

Copyright

© 2014, Stolfi 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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Further reading

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