Discrimination between Atlantic and Pacific subspecies of northern bluefin tuna (Thunnus thynnus) by magnetic-capture hybridization using bacterial magnetic particles

Haruko Takeyama, Hisahito Tsuzuki, Seinen Chow, Hideki Nakayama, Tadashi Matsunaga

Research output: Contribution to journalArticle

28 Citations (Scopus)


The previously developed magnetic-capture hybridization technique employing bacterial magnetic particles was applied to discriminate between Atlantic and Pacific subspecies of the northern bluefin tuna (Thunnus thynnus) using specific DNA sequences. Nucleotide sequences of a 925-bp fragment (ATCO) flanking the mitochondrial ATPase and cytochrome oxidase subunit III genes in these two subspecies were compared. Two regions having single-nucleotide and three-nucleotide differences between the subspecies were adopted to design DNA probes (NR1, 21-mer; NR2, 29-mer), and two internal primer sets were designed to amplify DNA fragments containing these regions. The DNA probes were immobilized on bacterial magnetic particles via streptavidin-biotin conjugation and subjected to magnetic-capture hybridization with the digoxigenin-labeled fragments amplified using the internal primers. The luminescence intensities of DNA on bacterial magnetic particles obtained by hybridization between the probes and the complementary fragments were higher than those obtained by hybridization with noncomplementary fragments. These data suggest that this system employing DNA on bacterial magnetic particles may be useful for discrimination of these two subspecies by recognizing a single-nucleotide difference.

Original languageEnglish
Pages (from-to)309-313
Number of pages5
JournalMarine Biotechnology
Issue number4
Publication statusPublished - 2000 Sep 20



  • Bacterial magnetic particles
  • Magnetic-capture hybridization
  • Northern bluefin tuna
  • Tuna species identification
  • mtDNA

ASJC Scopus subject areas

  • Biotechnology
  • Aquatic Science

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