Publication Date
10-29-2019
Document Type
Article
Organizational Units
College of Natural Science and Mathematics, Biological Sciences
Keywords
Extracellular matrix, Cell junctions, Freshwater sponge, Molecular composition
Abstract
The integrity and organization of animal tissues depend upon specialized protein complexes that mediate adhesion between cells with each other (cadherin-based adherens junctions), and with the extracellular matrix (integrin-based focal adhesions). Reconstructing how and when these cell junctions evolved is central to understanding early tissue evolution in animals. We examined focal adhesion protein homologs in tissues of the freshwater sponge, Ephydatia muelleri (phylum Porifera; class Demospongiae). Our principal findings are that (1) sponge focal adhesion homologs (integrin, talin, focal adhesion kinase, etc.) co-precipitate as a complex, separate from adherens junction proteins; (2) that actin-based structures resembling focal adhesions form at the cell–substrate interface, and their abundance is dynamically regulated in response to fluid shear; (3) focal adhesion proteins localize to both cell–cell and cell–extracellular matrix adhesions, and; (4) the adherens junction protein β-catenin is co-distributed with focal adhesion proteins at cell–cell junctions everywhere except the choanoderm, and at novel junctions between cells with spicules, and between cells with environmental bacteria. These results clarify the diversity, distribution and molecular composition of cell junctions in tissues of E. muelleri, but raise new questions about their functional properties and ancestry.
Copyright Date
10-29-2019
Copyright Statement / License for Reuse
This work is licensed under a Creative Commons Attribution 4.0 International License.
Rights Holder
The Authors
Provenance
Received from author
File Format
application/pdf
Language
English (eng)
Extent
16 pgs
File Size
3794 KB
Publication Statement
Copyright is held by the authors. User is responsible for all copyright compliance. This article was originally published as:
Mitchell, J. M., & Nichols, S. A. (2019). Diverse cell junctions with unique molecular composition in tissues of a sponge (Porifera). EvoDevo, 10(1), 1-16. DOI: 10.1186/s13227-019-0139-0
Publication Title
EvoDevo
Volume
10
Issue
1
First Page
1
Last Page
16
ISSN
3091-3446
Recommended Citation
Mitchell, J. M., & Nichols, S. A. (2019). Diverse cell junctions with unique molecular composition in tissues of a sponge (Porifera). EvoDevo, 10(1), 1-16. DOI: 10.1186/s13227-019-0139-0