A flagellate-to-amoeboid switch in the closest living relatives of animals

Abstract
Data availability
Article and author information
Metrics

Abstract

Amoeboid cells are fundamental to animal biology and broadly distributed across animal diversity, but their evolutionary origin is unclear. The closest living relatives of animals, the choanoflagellates, display a polarized cell architecture (with an apical flagellum encircled by microvilli) that closely resembles that of epithelial cells and suggests homology, but this architecture differs strikingly from the deformable phenotype of animal amoeboid cells. Here, we show that choanoflagellates subjected to confinement differentiate into an amoeboid form by retracting their flagella and activating myosin-based motility. This switch allows escape from confinement and is conserved across choanoflagellate diversity. The conservation of the amoeboid cell phenotype across animals and choanoflagellates, together with the conserved role of myosin, is consistent with the homology of amoeboid motility in both lineages. We hypothesize that the differentiation between animal epithelial and crawling cells might have evolved from a stress-induced phenotypic switch between flagellate and amoeboid forms in their single-celled ancestors.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files.

Article and author information

Author details

Thibaut Brunet

Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States

For correspondence
t.brunet@berkeley.edu

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0002-1843-1613
Marvin Albert

Department of Molecular Life Sciences, University of Zürich, Zürich, Switzerland

Competing interests
The authors declare that no competing interests exist.
William Roman

Instituto de Medicina Molecular João Lobo Antunes, Lisbon, Portugal

Competing interests
The authors declare that no competing interests exist.
Maxwell C Coyle

Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States

Competing interests
The authors declare that no competing interests exist.
Danielle C Spitzer

Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0003-4827-1857
Nicole King

Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States

For correspondence
nking@berkeley.edu

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0002-6409-1111

Funding

Howard Hughes Medical Institute

Nicole King

EMBO (ALTF 1474-2016)

Thibaut Brunet

Human Frontiers Science Program (000053/2017-L)

Thibaut Brunet

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

Copyright

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.