title: Metagenomic analysis of stressed coral holobionts.
abstract: The coral holobiont is the community of metazoans, protists and microbes associated with scleractinian corals. Disruptions in these associations have been correlated with coral disease, but little is known about the series of events involved in the shift from mutualism to pathogenesis. To evaluate structural and functional changes in coral microbial communities, Porites compressa was exposed to four stressors: increased temperature, elevated nutrients, dissolved organic carbon loading and reduced pH. Microbial metagenomic samples were collected and pyrosequenced. Functional gene analysis demonstrated that stressors increased the abundance of microbial genes involved in virulence, stress resistance, sulfur and nitrogen metabolism, motility and chemotaxis, fatty acid and lipid utilization, and secondary metabolism. Relative changes in taxonomy also demonstrated that coral-associated microbiota (Archaea, Bacteria, protists) shifted from a healthy-associated coral community (e.g. Cyanobacteria, Proteobacteria and the zooxanthellae Symbiodinium) to a community (e.g. Bacteriodetes, Fusobacteria and Fungi) of microbes often found on diseased corals. Additionally, low-abundance Vibrio spp. were found to significantly alter microbiome metabolism, suggesting that the contribution of a just a few members of a community can profoundly shift the health status of the coral holobiont.
authors.affiliation: Department of Biology, San Diego State University, San Diego, CA, USA. rvegathurber@gmail.com
authors.forename: Rebecca
authors.initials: R
authors.lastname: Vega Thurber
authors.forename: Dana
authors.initials: D
authors.lastname: Willner-Hall
authors.forename: Beltran
authors.initials: B
authors.lastname: Rodriguez-Mueller
authors.forename: Christelle
authors.initials: C
authors.lastname: Desnues
authors.forename: Robert A
authors.initials: RA
authors.lastname: Edwards
authors.forename: Florent
authors.initials: F
authors.lastname: Angly
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Dinsdale
authors.forename: Linda
authors.initials: L
authors.lastname: Kelly
authors.forename: Forest
authors.initials: F
authors.lastname: Rohwer
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000378:metabolism / Q000382:microbiology; D004141:Dinoflagellida / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D019605:Euryarchaeota / Q000235:genetics / Q000378:metabolism; D005658:Fungi / Q000254:growth & development; D023281:Genomics; D054892:Metagenome / Q000187:drug effects / Q000235:genetics*; D009584:Nitrogen / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics*; D013559:Symbiosis; D013696:Temperature; D014733:Vibrio / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics
chemical_list: D009584:Nitrogen