title: Universal primers and PCR of gut contents to study marine invertebrate diets.
abstract: Determining the diets of marine invertebrates by gut content analysis is problematic. Many consumed organisms become unrecognizable once partly digested, while those with hard remains (e.g. diatom skeletons) may bias the analysis. Here, we adapt DNA-based methods similar to those used for microbial diversity surveys as a novel approach to study the diets of macrophagous (the deep-sea amphipods Scopelocheirus schellenbergi and Eurythenes gryllus) and microphagous (the bivalve Lucinoma aequizonata) feeders in the deep sea. Polymerase chain reaction (PCR) in conjunction with 'universal' primers amplified portions of the mitochondrial cytochrome c oxidase I (COI) gene for animals ingested by S. schellenbergi and E. gryllus and the 18S rRNA gene for lesser eukaryotes ingested by L. aequizonata. Amplified sequences were combined with sequences from GenBank to construct phylogenetic trees of ingested organisms. Our analyses indicate that S. schellenbergi, E. gryllus and L. aequizonata diets are considerably more diverse than previously thought, casting new light on the foraging strategies of these species. Finally, we discuss the strengths and weaknesses of this technique and its potential applicability to diet analyses of other invertebrates.
authors.affiliation: Marine Biology Research Division, Scripps Institution of Oceanography, 9500 Gilman Dr. 0208, La Jolla CA 92093, USA. lblanken@ucsd.edu
authors.forename: L E
authors.initials: LE
authors.lastname: Blankenship
authors.forename: A A
authors.initials: AA
authors.lastname: Yayanos
mesh_terms: D000818:Animals; D001483:Base Sequence; D019295:Computational Biology; D017931:DNA Primers / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics; D005766:Gastrointestinal Contents / Q000737:chemistry*; D006239:Haplotypes / Q000235:genetics; D007448:Invertebrates; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques; D010140:Pacific Ocean; D010802:Phylogeny; D010933:Plankton / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D012337:RNA, Ribosomal, 18S; D003576:Electron Transport Complex IV