Comparative genomics and the nature of placozoan species

• DOI: 10.1371/journal.pbio.2005359
• Publication Date: 2018-07-31T22:42:36Z
• Authors: Michael Eitel; Warren R. Francis; Frédérique Varoqu...; Jean Daraspe; Hans-Jürgen Osigus; Stefan Krebs; Sergio Vargas; Helmut Blum; Gray A. Williams; Bernd Schierwater; Gert Wörheide
• Keywords: Lineage (genetic); Comparative Genomics; Genetic algorithm; Convergent evolution; Species complex

Placozoans are a phylum of nonbilaterian marine animals currently represented by single described species, Trichoplax adhaerens, Schulze 1883. arguably show the simplest animal morphology, which is identical among isolates collected worldwide, despite an apparently sizeable genetic diversity within phylum. Here, we use comparative genomics approach for deeper appreciation structure and causes deeply diverging lineages in Placozoa. We generated high-quality draft genome lineage H13 isolated from Hong Kong compared it to distantly related T. adhaerens. uncovered substantial structural differences between two genomes that point deep genomic separation provide support adaptation gene duplication likely crucial mechanism placozoan speciation. further evidence reproductively species suggest genus-level difference justifying designation as new Hoilungia hongkongensis nov. gen., spec., now second first genus. Our multilevel is, therefore, prove valuable distinctions other cryptic microscopic groups lack diagnostic morphological characters, such some nematodes, copepods, rotifers, or mites.