RT Journal Article
SR Electronic
T1 A universal subcuticular bacterial symbiont of a coral predator, the crown-of-thorns starfish
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.02.13.947093
DO 10.1101/2020.02.13.947093
A1 Naohisa Wada
A1 Hideaki Yuasa
A1 Rei Kajitani
A1 Yasuhiro Gotoh
A1 Yoshitoshi Ogura
A1 Dai Yoshimura
A1 Atsushi Toyoda
A1 Sen-Lin Tang
A1 Yukio Higashimura
A1 Hugh Sweatman
A1 Zac Forsman
A1 Omri Bronstein
A1 Gal Eyal
A1 Nalinee Thongtham
A1 Takehiko Itoh
A1 Tetsuya Hayashi
A1 Nina Yasuda
YR 2020
UL http://biorxiv.org/content/early/2020/02/14/2020.02.13.947093.abstract
AB Background Population outbreaks of the crown-of-thorns starfish (Acanthaster planci sensu lato;COTS), a primary predator of reef-building corals in the Indo-Pacific Ocean, are major concerns in coral reefs management. While biological and ecological knowledge on COTS has been accumulated since the 1960s, little is known about their associated bacteria. The aim of this study was to provide fundamental information on dominant COTS-associated bacteria by multi-disciplinary approach.Methods We first conducted 16S rRNA metabarcoding for bacterial profiles on different body parts of COTS, and obtained full-length 16S rRNA gene sequence of the single dominant bacterium for phylogenetic analysis. A total 205 COTS individuals from 17 locations throughout the Indo-Pacific Ocean was examined for the presence of COTS associated bacteria (named COTS27). The COTS27 localization was visualized by Fluorescence in situ hybridization (FISH) using a COTS27-specific probe. Furthermore, COTS27 chromosome genome was reconstructed from the hologenome sequence data of COTS.Results We discovered that a single bacterium exists at high densities in the subcuticular space of COTS forming a biofilm-like structure over the entire body surface of COTS. COTS27 belongs to a clade that presumably represents a distinct order (so-called marine spirochetes) in the phylum Spirochaetes and is universally present in COTS throughout the Indo-Pacific Ocean. The reconstructed genome of COT27 includes some genetic traits that are probably linked to adaptation to marine environments and evolution as an extracellular endosymbiont in subcuticular spaces.Conclusions COTS27 can be found in the allopatrically spectated 3 different COTS species, ranging from northern Red Sea to the central Pacific, implying symbiotic relationship started before speciation (about 2 million years ago). The universal and nearly mono-specific association of COTS27 with COTS potentially provides a useful model system to study symbiont-host interactions in marine invertebrates.CDDConserved Domain DatabaseCDSsprotein-coding sequencesCOGClusters of Orthologous GroupsCOTSCrown-of-thorns starfishFISHFluorescence in situ hybridizationKEGGKyoto Encyclopedia of Genes and GenomesMLMaximum likelihoodNJNeighbour joiningNADNicotinamide adenine dinucleotideNa+-NQSodium-pumping NADH:ubiquinone oxidoreductaseOTUOperational taxonomic unitSCBSubcuticular bacteria