title: Distinct antimicrobial peptide expression determines host species-specific bacterial associations.
abstract: Animals are colonized by coevolved bacterial communities, which contribute to the host's health. This commensal microbiota is often highly specific to its host-species, inferring strong selective pressures on the associated microbes. Several factors, including diet, mucus composition, and the immune system have been proposed as putative determinants of host-associated bacterial communities. Here we report that species-specific antimicrobial peptides account for different bacterial communities associated with closely related species of the cnidarian Hydra. Gene family extensions for potent antimicrobial peptides, the arminins, were detected in four Hydra species, with each species possessing a unique composition and expression profile of arminins. For functional analysis, we inoculated arminin-deficient and control polyps with bacterial consortia characteristic for different Hydra species and compared their selective preferences by 454 pyrosequencing of the bacterial microbiota. In contrast to control polyps, arminin-deficient polyps displayed decreased potential to select for bacterial communities resembling their native microbiota. This finding indicates that species-specific antimicrobial peptides shape species-specific bacterial associations.
authors.affiliation: Zoological Institute, Christian-Albrechts University of Kiel, 24098 Kiel, Germany.
authors.forename: Sören
authors.initials: S
authors.lastname: Franzenburg
authors.forename: Jonas
authors.initials: J
authors.lastname: Walter
authors.forename: Sven
authors.initials: S
authors.lastname: Künzel
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: John F
authors.initials: JF
authors.lastname: Baines
authors.forename: Thomas C G
authors.initials: TC
authors.lastname: Bosch
authors.forename: Sebastian
authors.initials: S
authors.lastname: Fraune
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism*; D001419:Bacteria / Q000254:growth & development / Q000276:immunology*; D018920:Coculture Techniques; D015169:Colony Count, Microbial; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D058507:Host Specificity; D006829:Hydra / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology*; D064307:Microbiota; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D023181:Antimicrobial Cationic Peptides
keywords: Cnidaria; core microbiota; holobiont; host-microbe; phylosymbiotic