Int. J. Dev. Biol. 61: 697 - 722 (2017)

https://doi.org/10.1387/ijdb.170202sb

Vol 61, Issue 10-11-12

Special Issue: The Amphioxus Model System

Developmental cell-cell communication pathways in the cephalochordate amphioxus: actors and functions

Published: 20 December 2017

Stephanie Bertrand*^,1, Yann Le Petillon¹, Ildikó M.L. Somorjai^2,3 and Hector Escriva*^,1

¹Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Banyuls/Mer, France, ²Gatty Marine Laboratory, Scottish Oceans Institute, East Sands, University of St Andrews, St Andrews, Scotland, UK and ³Biomedical Sciences Research Complex, North Haugh, University of St Andrews, St Andrews, Scotland, UK

Abstract

During embryonic development, cells of metazoan embryos need to communicate in order to construct the correct bodyplan. To do so, they use several signals that usually act through interactions between ligands and receptors. Interestingly, only a few pathways are known to be fundamental during animal development, and they are usually found in all the major metazoan clades, raising the following question: how have evolution of the actors and of the functions of these pathways participated in the appearance of the current diversity of animal morphologies? The chordate lineage comprises vertebrates, their sister group the urochordates, and the cephalochordates (i.e. amphioxus). Urochordates are quite derived relative to the chordate ancestor, whereas cephalochordates and vertebrates share many morphological traits. Thus, comparing embryonic development between vertebrates and cephalochordates should give us some insight into the ancestral characters present in chordates and into the morphological evolution in this clade. However, while much is known about the function of different signalling pathways in vertebrates, data are still scarce in the literature for cephalochordates. In this review, we summarize the current state of the field concerning the expression of actors and the function of the major cell-cell communication pathways, including Hedgehog (Hh), Notch, Nuclear Receptor (NR), Receptor Tyrosine Kinase (RTK), Transforming Growth Factor-β (TGF-β) and Wingless/Int (Wnt), in amphioxus.

Keywords

chordates, evolution, development, signalling pathways