The evolutionary origin of bilaterian smooth and striated myocytes
- Howard Hughes Medical Institute, University of California, Berkeley, United States
- Ludwig-Maximilians University Munich, Germany
- University of Bergen, Norway
- Helmholtz Zentrum München, Germany
- European Molecular Biology Laboratory, Germany
Abstract
The dichotomy between smooth and striated myocytes is fundamental for bilaterian musculature, but its evolutionary origin is unsolved. In particular, interrelationships of visceral smooth muscles remain unclear. Absent in fly and nematode, they have not yet been characterized molecularly outside vertebrates. Here, we characterize expression profile, ultrastructure, contractility and innervation of the musculature in the marine annelid Platynereis dumerilii and identify smooth muscles around the midgut, hindgut and heart that resemble their vertebrate counterparts in molecular fingerprint, contraction speed, and nervous control. Our data suggest that both visceral smooth and somatic striated myocytes were present in the protostome-deuterostome ancestor, and that smooth myocytes later co-opted the striated contractile module repeatedly - for example in vertebrate heart evolution. During these smooth-to-striated myocyte conversions the core regulatory complex of transcription factors conveying myocyte identity remained unchanged, reflecting a general principle in cell type evolution.
Article and author information
Author details
Funding
European Research Council (Brain Evo-Devo)
- Thibaut Brunet
- Paola Bertucci
- Detlev Arendt
European Union's Seventh Framework Program (EVONET)
- Antonella Lauri
European Union-Marie Curie Early Training Network (ZOONET)
- Antje HL Fischer
European Molecular Biology Laboratory (International PhD Program)
- Thibaut Brunet
- Antje HL Fischer
- Patrick RH Steinmetz
- Antonella Lauri
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2016, Brunet 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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The evolutionary origin of bilaterian smooth and striated myocytes
eLife 5:e19607.
https://doi.org/10.7554/eLife.19607
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