Genome based analyses of six hexacorallian species reject the “naked coral” hypothesis

• Published in: Genome Biology and Evolution
• Main Authors: Wang, Xin, Drillon, Guénola, Ryu, Taewoo, Voolstra, Christian R., Aranda, Manuel
• Other Authors: Biological and Environmental Sciences and Engineering (BESE) Division, Marine Science Program, Red Sea Research Center (RSRC), Sorbonne Universités, UPMC-Univ P6, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative - UMR 7238, 4 Place Jussieu, Paris, 75005, France, APEC Climate Center, Busan 48058, South Korea
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Oxford University Press (OUP) 2017
• Subjects: naked corals; Scleractinia; Corallimorpharia; phylogenomics; evolution; calcification; Ocean acidification
• Online Access: http://hdl.handle.net/10754/625855; https://doi.org/10.1093/gbe/evx196

Scleractinian corals are the foundation species of the coral-reef ecosystem. Their calcium carbonate skeletons form extensive structures that are home to millions of species, making coral reefs one of the most diverse ecosystems of our planet. However, our understanding of how reef-building corals have evolved the ability to calcify and become the ecosystem builders they are today is hampered by uncertain relationships within their subclass Hexacorallia. Corallimorpharians have been proposed to originate from a complex scleractinian ancestor that lost the ability to calcify in response to increasing ocean acidification, suggesting the possibility for corals to lose and gain the ability to calcify in response to increasing ocean acidification. Here we employed a phylogenomic approach using whole-genome data from six hexacorallian species to resolve the evolutionary relationship between reef-building corals and their non-calcifying relatives. Phylogenetic analysis based on 1,421 single-copy orthologs, as well as gene presence/absence and synteny information, converged on the same topologies, showing strong support for scleractinian monophyly and a corallimorpharian sister clade. Our broad phylogenomic approach using sequence-based and sequence-independent analyses provides unambiguous evidence for the monophyly of scleractinian corals and the rejection of corallimorpharians as descendants of a complex coral ancestor. We thank Yi Jin Liew for help with the bioinformatic analyses and helpful discussions that greatly improved the manuscript.