Insights & Perspectives
An epithelial tissue in Dictyostelium challenges the traditional origin of metazoan multicellularity
Article first published online: 29 AUG 2012
Copyright © 2012 WILEY Periodicals, Inc.
Volume 34, Issue 10, pages 833–840, October 2012
How to Cite
Dickinson, D. J., Nelson, W. J. and Weis, W. I. (2012), An epithelial tissue in Dictyostelium challenges the traditional origin of metazoan multicellularity. Bioessays, 34: 833–840. doi: 10.1002/bies.201100187
- Issue published online: 13 SEP 2012
- Article first published online: 29 AUG 2012
- metazoan evolution;
We hypothesize that aspects of animal multicellularity originated before the divergence of metazoans from fungi and social amoebae. Polarized epithelial tissues are a defining feature of metazoans and contribute to the diversity of animal body plans. The recent finding of a polarized epithelium in the non-metazoan social amoeba Dictyostelium discoideum demonstrates that epithelial tissue is not a unique feature of metazoans, and challenges the traditional paradigm that multicellularity evolved independently in social amoebae and metazoans. An alternative view, presented here, is that the common ancestor of social amoebae, fungi, and animals spent a portion of its life cycle in a multicellular state and possessed molecular machinery necessary for forming an epithelial tissue. Some descendants of this ancestor retained multicellularity, while others reverted to unicellularity. This hypothesis makes testable predictions regarding tissue organization in close relatives of metazoans and provides a novel conceptual framework for studies of early animal evolution.
Editor's suggested further reading in BioEssays Searching for Eve: Basal metazoans and the evolution of multicellular complexity Abstract