title: Diversity and distribution of unicellular opisthokonts along the European coast analysed using high-throughput sequencing.
abstract: The opisthokonts are one of the major super groups of eukaryotes. It comprises two major clades: (i) the Metazoa and their unicellular relatives and (ii) the Fungi and their unicellular relatives. There is, however, little knowledge of the role of opisthokont microbes in many natural environments, especially among non-metazoan and non-fungal opisthokonts. Here, we begin to address this gap by analysing high-throughput 18S rDNA and 18S rRNA sequencing data from different European coastal sites, sampled at different size fractions and depths. In particular, we analyse the diversity and abundance of choanoflagellates, filastereans, ichthyosporeans, nucleariids, corallochytreans and their related lineages. Our results show the great diversity of choanoflagellates in coastal waters as well as a relevant representation of the ichthyosporeans and the uncultured marine opisthokonts (MAOP). Furthermore, we describe a new lineage of marine fonticulids (MAFO) that appears to be abundant in sediments. Taken together, our work points to a greater potential ecological role for unicellular opisthokonts than previously appreciated in marine environments, both in water column and sediments, and also provides evidence of novel opisthokont phylogenetic lineages. This study highlights the importance of high-throughput sequencing approaches to unravel the diversity and distribution of both known and novel eukaryotic lineages.
authors.affiliation: Institut de Biologia Evolutiva (CSIC-UPF), Passeig Marítim de la Barceloneta 37-49, 08003, Barcelona, Catalonia, Spain.
authors.forename: Javier
authors.identifier: http://orcid.org/0000-0002-5292-1421
authors.initials: J
authors.lastname: Del Campo
authors.affiliation: Department of Biochemistry, Genetics and Immunology, University of Vigo, Vigo, Galicia, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Mallo
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Passeig Marítim de la Barceloneta 37-49, 08003, Barcelona, Catalonia, Spain.
authors.forename: Ramon
authors.initials: R
authors.lastname: Massana
authors.affiliation: CNRS, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, UMR 7144, Roscoff, France.|Station Biologique de Roscoff, UPMC University Paris 06, Roscoff, UMR 7144, France.
authors.forename: Colomban
authors.initials: C
authors.lastname: de Vargas
authors.affiliation: Geoffrey Pope Building, Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK.|Canadian Institute for Advanced Research, CIFAR Program in Integrated Microbial Biodiversity, Toronto, Canada.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Richards
authors.affiliation: Institut de Biologia Evolutiva (CSIC-UPF), Passeig Marítim de la Barceloneta 37-49, 08003, Barcelona, Catalonia, Spain.|Departament de Genètica, Universitat de Barcelona, Barcelona, Catalonia, Spain.|Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain.
authors.forename: Iñaki
authors.initials: I
authors.lastname: Ruiz-Trillo
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000235:genetics*; D001483:Base Sequence; D044822:Biodiversity; D056897:Choanoflagellata / Q000145:classification / Q000235:genetics / Q000502:physiology*; D004275:DNA, Ribosomal / Q000235:genetics; D005060:Europe; D005658:Fungi / Q000145:classification / Q000235:genetics / Q000502:physiology; D014644:Genetic Variation / Q000235:genetics; D019015:Geologic Sediments; D050298:Mesomycetozoea / Q000145:classification / Q000235:genetics / Q000502:physiology; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics
chemical_list: D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S