| Project/Area Number |
17580058
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied microbiology
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| Research Institution | The University of Tokyo |
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Principal Investigator |
TSUKAMOTO Kumiko The University of Tokyo, Ocean Research Institute, Technician (30396923)
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| Co-Investigator(Kenkyū-buntansha) |
WADA Minoru The University of Tokyo, Ocean Research Institute, Assistant Professor (70292860)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,870,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥270,000)
Fiscal Year 2007: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2006: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2005: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Bioluminescent bacteria / Bacterial species concept / Symbiosis |
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| Research Abstract |
Photobacterium leiognathi is a bioluminescent bacterium, widely distributing in the marine environment. Some are present as light organ symbionts of fish species belonging to the families of Leiognathidae, Acropomatidae and Apogonide. Based on luciferase gene(lux) phylogeny, the symbionts of leiognathid fish formed a tight cluster apart from those of non-leiognathid fish species. The aim of this work was to clarify how the two clades had been speciated as different bacterial species. We conducted phylogenetic and MLST analysis based on five housekeeping genes (gyrB, ftsZ, mreB, topA and 16S rRNA) of the isolates.
We used 37 isolates of P. leiognathi from light organs of four different fish, Leiognathus nuchalis, L. rivulatus, Acropoma japonicus and Siphamia versicolor for phylogenetic analysis and 15 out of 37 for MLST analysis. The two distinctive clades which were confirmed with lux gene were not detected with both each housekeeping gene and concatenated sequence. Moreover, the MLST analysis using five housekeeping genes revealed no identical sequence type among 15 isolates. The results indicated that only the luminescent system of this bacterium specifically diverged depending on the host species. Genetic variation, which indicate different bacterial species, were not accumulated on other housekeeping genes used in this study.
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