title: Siboglinid-bacteria endosymbiosis: A model system for studying symbiotic mechanisms.
abstract: Siboglinid worms are a group of gutless marine annelids which are nutritionally dependent upon endosymbiotic bacteria.1,2 Four major groups of siboglinids are known including vestimentiferans, Osedax spp., frenulates and moniliferans.3-5 Very little is known about the diversity of bacterial endosymbionts associated with frenulate or monoliferan siboglinids. This lack of knowledge is surprising considering the global distribution of siboglinids; this system is likely among the most common symbioses in the deep sea. At least three distinct clades of endosymbiotic gamma-proteobacteria associate with siboglinid annelids.6 Frenulates harbor a clade of gamma-proteobacteria that are divergent from both the thiotrophic bacteria of vestimentiferans and monoliferans as well as the heterotrophic bacteria of Osedax spp.6,7 We also discuss priorities for future siboglinid research and the need to move beyond descriptive studies. A promising new method, laser-capture microdissection (LCM), allows for the precise excision of tissue regions of interest.8 This method, when used in concert with molecular and genomic techniques, such as Expressed Sequence Tag (EST) surveys using pyrosequencing technology, will likely enable investigations into physiological processes and mechanisms in these symbioses. Furthermore, adopting a comparative approach using different siboglinid groups, such as worms harboring thiotrophic versus methanotrophic endosymbionts, may yield considerable insight into the ecology and evolution of the Siboglinidae.
authors.affiliation: Department of Biological Sciences; Auburn University; Auburn, Alabama USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Thornhill
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Fielman
authors.forename: Scott R
authors.initials: SR
authors.lastname: Santos
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Halanych
references.citation: Proc Biol Sci. 2005 Dec 22;272(1581):2587-92
references.pmid: 16321780
references.citation: Biol Bull. 2008 Apr;214(2):135-44
references.pmid: 18400995
references.citation: Biol Bull. 2001 Aug;201(1):65-75
references.pmid: 11526065
references.citation: J Bacteriol. 1988 Jun;170(6):2506-10
references.pmid: 3286609
references.citation: Mar Biotechnol (NY). 2005 Sep-Oct;7(5):416-28
references.pmid: 16088356
references.citation: Science. 2004 Jul 30;305(5684):668-71
references.pmid: 15286372
references.citation: Appl Environ Microbiol. 2007 Apr;73(7):2314-23
references.pmid: 17277220
references.citation: Bioinformatics. 2001 Aug;17(8):754-5
references.pmid: 11524383
references.citation: Science. 1981 Jul 17;213(4505):336-8
references.pmid: 17819905
references.citation: Environ Microbiol. 2008 Dec;10(12):3237-54
references.pmid: 18707616
references.citation: Biol Bull. 2008 Jun;214(3):255-65
references.pmid: 18574102
references.citation: Mar Biotechnol (NY). 2003 May-Jun;5(3):261-9
references.pmid: 14502398
references.citation: Nat Protoc. 2006;1(2):586-603
references.pmid: 17406286
references.citation: Proc Natl Acad Sci U S A. 1998 Aug 18;95(17):9962-6
references.pmid: 9707583