title: Deep sequencing reveals exceptional diversity and modes of transmission for bacterial sponge symbionts.
abstract: Marine sponges contain complex bacterial communities of considerable ecological and biotechnological importance, with many of these organisms postulated to be specific to sponge hosts. Testing this hypothesis in light of the recent discovery of the rare microbial biosphere, we investigated three Australian sponges by massively parallel 16S rRNA gene tag pyrosequencing. Here we show bacterial diversity that is unparalleled in an invertebrate host, with more than 250,000 sponge-derived sequence tags being assigned to 23 bacterial phyla and revealing up to 2996 operational taxonomic units (95% sequence similarity) per sponge species. Of the 33 previously described 'sponge-specific' clusters that were detected in this study, 48% were found exclusively in adults and larvae - implying vertical transmission of these groups. The remaining taxa, including 'Poribacteria', were also found at very low abundance among the 135,000 tags retrieved from surrounding seawater. Thus, members of the rare seawater biosphere may serve as seed organisms for widely occurring symbiont populations in sponges and their host association might have evolved much more recently than previously thought.
authors.affiliation: Australian Institute of Marine Science, PMB 3, Townsville Mail Centre, Qld 4810, Australia.
authors.forename: Nicole S
authors.initials: NS
authors.lastname: Webster
authors.forename: Michael W
authors.initials: MW
authors.lastname: Taylor
authors.forename: Faris
authors.initials: F
authors.lastname: Behnam
authors.forename: Sebastian
authors.initials: S
authors.lastname: Lücker
authors.forename: Thomas
authors.initials: T
authors.lastname: Rattei
authors.forename: Stephen
authors.initials: S
authors.lastname: Whalan
authors.forename: Matthias
authors.initials: M
authors.lastname: Horn
authors.forename: Michael
authors.initials: M
authors.lastname: Wagner
mesh_terms: D000818:Animals; D001315:Australia; D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000254:growth & development; D044822:Biodiversity; D004269:DNA, Bacterial / Q000235:genetics; D059014:High-Throughput Nucleotide Sequencing; D054892:Metagenome; D008969:Molecular Sequence Data; D010802:Phylogeny; D011161:Porifera / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013559:Symbiosis
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S