title: Zooplankton diversity analysis through single-gene sequencing of a community sample.
abstract: BACKGROUND
  Oceans cover more than 70% of the earth's surface and are critical for the homeostasis of the environment. Among the components of the ocean ecosystem, zooplankton play vital roles in energy and matter transfer through the system. Despite their importance, understanding of zooplankton biodiversity is limited because of their fragile nature, small body size, and the large number of species from various taxonomic phyla. Here we present the results of single-gene zooplankton community analysis using a method that determines a large number of mitochondrial COI gene sequences from a bulk zooplankton sample. This approach will enable us to estimate the species richness of almost the entire zooplankton community.
  
  
  RESULTS
  A sample was collected from a depth of 721 m to the surface in the western equatorial Pacific off Pohnpei Island, Micronesia, with a plankton net equipped with a 2-m2 mouth opening. A total of 1,336 mitochondrial COI gene sequences were determined from the cDNA library made from the sample. From the determined sequences, the occurrence of 189 species of zooplankton was estimated. BLASTN search results showed high degrees of similarity (>98%) between the query and database for 10 species, including holozooplankton and merozooplankton.
  
  
  CONCLUSIONS
  In conjunction with the Census of Marine Zooplankton and Barcode of Life projects, single-gene zooplankton community analysis will be a powerful tool for estimating the species richness of zooplankton communities.
authors.affiliation: Ocean Research Institute, University of Tokyo, 1-15-1 Minamidai, Nakano-ku, Tokyo 164-8639, Japan. ryuji@ori.u-tokyo.ac.jp
authors.forename: Ryuji J
authors.initials: RJ
authors.lastname: Machida
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Hashiguchi
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Nishida
authors.forename: Shuhei
authors.initials: S
authors.lastname: Nishida
mesh_terms: D000818:Animals; D044822:Biodiversity; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D015723:Gene Library; D050259:Genes, Mitochondrial; D008849:Micronesia; D010140:Pacific Ocean; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics; D017422:Sequence Analysis, DNA; D015048:Zooplankton / Q000145:classification / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial; D012333:RNA, Messenger; D003576:Electron Transport Complex IV