Home » Key Scientific Articles » Structural molecular components of septate junctions in cnidarians point to the origin of epithelial junctions in eukaryotes.

Structural molecular components of septate junctions in cnidarians point to the origin of epithelial junctions in eukaryotes.

Journal Reference

Ganot P1, Zoccola D2, Tambutté E2, Voolstra CR3, Aranda M3, Allemand D2, Tambutté S2. Mol Biol Evol. 2015 Jan;32(1):44-62.

Show Affiliations

1Marine Biology Department, Centre Scientifique de Monaco, Quai Antoine Premier, Monaco [email protected] and

2Marine Biology Department, Centre Scientifique de Monaco, Quai Antoine Premier, Monaco.and

3Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.

 

Abstract

Septate junctions (SJs) insure barrier properties and control paracellular diffusion of solutes across epithelia in invertebrates. However, the origin and evolution of their molecular constituents in Metazoa have not been firmly established. Here, we investigated the genomes of early branching metazoan representatives to reconstruct the phylogeny of the molecular components of SJs. Although Claudins and SJ cytoplasmic adaptor components appeared successively throughout metazoan evolution, the structural components of SJs arose at the time of Placozoa/Cnidaria/Bilateria radiation. We also show that in the scleractinian coral Stylophora pistillata, the structural  SJ component Neurexin IV colocalizes with the cortical actin network at the apical border of the cells, at the place of SJs. We propose a model for SJ components in Cnidaria. Moreover, our study reveals an unanticipated diversity of SJ structural component variants in cnidarians. This diversity correlates with gene-specific expression in calcifying and noncalcifying tissues, suggesting specific paracellular pathways across the cell layers of these diploblastic animals.

© The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved.

Go To PubMed

 

Structural Molecular Components of Septate Junctions in Cnidarians Point to the Origin of Epithelial Junctions in Eukaryotes