Retracing the path of planar cell polarity

BMC Evolutionary Biology

Research Article

Emmanuelle Renard¹  Laura Fierro-Constain¹  Quentin Schenkelaars²  Carole Borchiellini² 

[1] Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale (IMBE UMR 7263), Aix Marseille Université, CNRS, IRD, Avignon Université, Station marine d’Endoume, Batterie des Lions, 13007, Marseille, France;Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale (IMBE UMR 7263), Aix Marseille Université, CNRS, IRD, Avignon Université, Station marine d’Endoume, Batterie des Lions, 13007, Marseille, France;Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (IGe3), Faculty of Sciences, University of Geneva, Geneva, Switzerland;

关键词: Planar cell polarity;    Van Gogh;    Multigene families;    Porifera;    Placozoa;    Ctenophora;    Wnt signaling;    Metazoan phylogeny;   

DOI  :  10.1186/s12862-016-0641-0

 received in 2015-11-25, accepted in 2016-03-22,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundThe Planar Cell Polarity pathway (PCP) has been described as the main feature involved in patterning cell orientation in bilaterian tissues. Recently, a similar phenomenon was revealed in cnidarians, in which the inhibition of this pathway results in the absence of cilia orientation in larvae, consequently proving the functional conservation of PCP signaling between Cnidaria and Bilateria. Nevertheless, despite the growing accumulation of databases concerning basal lineages of metazoans, very few information concerning the existence of PCP components have been gathered outside of Bilateria and Cnidaria. Thus, the origin of this module or its prevalence in early emerging metazoans has yet to be elucidated.ResultsThe present study addresses this question by investigating the genomes and transcriptomes from all poriferan lineages in addition to Trichoplax (Placozoa) and Mnemiopsis (Ctenophora) genomes for the presence of the core components of this pathway. Our results confirm that several PCP components are metazoan innovations. In addition, we show that all members of the PCP pathway, including a bona fide Strabismus ortholog (Van gogh), are retrieved only in one sponge lineage (Homoscleromorpha) out of four. This highly suggests that the full PCP pathway dates back at least to the emergence of homoscleromorph sponges. Consequently, several secondary gene losses would have occurred in the three other poriferan lineages including Amphimedon queenslandica (Demospongiae). Several proteins were not retrieved either in placozoans or ctenophores leading us to discuss the difficulties to predict orthologous proteins in basally branching animals. Finally, we reveal how the study of multigene families may be helpful to unravel the relationships at the base of the metazoan tree.ConclusionThe PCP pathway antedates the radiation of Porifera and may have arisen in the last common ancestor of animals. Oscarella species now appear as key organisms to understand the ancestral function of PCP signaling and its potential links with Wnt pathways.

【 授权许可】

CC BY   
© Schenkelaars et al. 2016