Updated on 2024/12/24

写真a

 
HAYAKAWA Tohru
 
Organization
Faculty of Interdisciplinary Science and Engineering in Health Systems Assistant Professor
Position
Assistant Professor
External link

Degree

  • Ph.D ( Hokkaido University )

Research Interests

  • Soil bacterium

  • Insect pathology

  • Mosquito control agents

  • Biotechnology

  • Pore-forming toxin

Research Areas

  • Environmental Science/Agriculture Science / Insect science

Education

  • Hokkaido University   大学院農学研究科  

    1993.4 - 1996.3

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    Country: Japan

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  • Kyoto Institute of Technology   大学院工芸科学研究科  

    1991.4 - 1993.3

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    Country: Japan

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  • Kyoto Institute of Technology   繊維学部   応用生物学

    1987.4 - 1991.3

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    Country: Japan

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Research History

  • 学術研究院ヘルスシステム統合科学学域   助教

    2021.4

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    Country:Japan

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  • Okayama University   Graduate School of Interdisciplinary Science and Engineering in Health Systems   Assistant Professor

    2018.4 - 2021.3

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    Country:Japan

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  • Okayama University   The Graduate School of Natural Science and Technology   Assistant Professor

    2005.4 - 2018.3

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    Country:Japan

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  • Niigata University   Graduate School of Science and Technology   Research Assistant

    1999.9 - 2005.3

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    Country:Japan

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  • University of California, Davis   Department of Entomology   Research scientist

    1996.8 - 1999.8

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    Country:United States

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Professional Memberships

 

Papers

  • Mutational analysis of the transmembrane α4-helix of Bacillus thuringiensis mosquito-larvicidal Cry4Aa toxin. Reviewed International journal

    Hirokazu Takahashi, Mami Asakura, Toru Ide, Tohru Hayakawa

    Current microbiology   81 ( 3 )   80 - 80   2024.1

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    Cry4Aa, produced by Bacillus thuringiensis subsp. israelensis, exhibits specific toxicity to larvae of medically important mosquito genera. Cry4Aa functions as a pore-forming toxin, and a helical hairpin (α4-loop-α5) of domain I is believed to be the transmembrane domain that forms toxin pores. Pore formation is considered to be a central mode of Cry4Aa action, but the relationship between pore formation and toxicity is poorly understood. In the present study, we constructed Cry4Aa mutants in which each polar amino acid residues within the transmembrane α4 helix was replaced with glutamic acid. Bioassays using Culex pipiens mosquito larvae and subsequent ion permeability measurements using symmetric KCl solution revealed an apparent correlation between toxicity and toxin pore conductance for most of the Cry4Aa mutants. In contrast, the Cry4Aa mutant H178E was a clear exception, almost losing its toxicity but still exhibiting a moderately high conductivity of about 60% of the wild-type. Furthermore, the conductance of the pore formed by the N190E mutant (about 50% of the wild-type) was close to that of H178E, but the toxicity was significantly higher than that of H178E. Ion selectivity measurements using asymmetric KCl solution revealed a significant decrease in cation selectivity of toxin pores formed by H178E compared to N190E. Our data suggest that the toxicity of Cry4Aa is primarily pore related. The formation of toxin pores that are highly ion-permeable and also highly cation-selective may enhance the influx of cations and water into the target cell, thereby facilitating the eventual death of mosquito larvae.

    DOI: 10.1007/s00284-023-03602-8

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  • Random Mutational Analysis Targeting Residue K155 within the Transmembrane β-Hairpin of the Mosquitocidal Mpp46Ab Toxin Invited Reviewed

    Midoka Miyazaki, Mami Asakura, Toru Ide, Tohru Hayakawa

    Biology   12 ( 12 )   1481 - 1481   2023.12

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:MDPI AG  

    Mpp46Ab is a mosquito-larvicidal pore-forming toxin derived from Bacillus thuringiensis TK-E6. Pore formation is believed to be a central mode of Mpp46Ab action, and the cation selectivity of the channel pores, in particular, is closely related to its mosquito-larvicidal activity. In the present study, we constructed a mutant library in which residue K155 within the transmembrane β-hairpin was randomly replaced with other amino acid residues. Upon mutagenesis and following primary screening using Culex pipiens mosquito larvae, we obtained 15 mutants in addition to the wild-type toxin. Bioassays using purified proteins revealed that two mutants, K155E and K155I, exhibited toxicity significantly higher than that of the wild-type toxin. Although increased cation selectivity was previously reported for K155E channel pores, we demonstrated in the present study that the cation selectivity of K155I channel pores was also significantly increased. Considering the characteristics of the amino acids, the charge of residue 155 may not directly affect the cation selectivity of Mpp46Ab channel pores. Replacement of K155 with glutamic acid or isoleucine may induce a similar conformational change in the region associated with the ion selectivity of the Mpp46Ab channel pores. Mutagenesis targeting the transmembrane β-hairpin may be an effective strategy for enhancing the ion permeability of the channel pores and the resulting mosquito-larvicidal activity of Mpp46Ab.

    DOI: 10.3390/biology12121481

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  • Crystal structure of the in-cell Cry1Aa purified from Bacillus thuringiensis Reviewed

    Junko Tanaka, Satoshi Abe, Tohru Hayakawa, Mariko Kojima, Keitaro Yamashita, Kunio Hirata, Takafumi Ueno

    Biochemical and Biophysical Research Communications   685   149144 - 149144   2023.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.bbrc.2023.149144

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  • Characteristics of channel pores formed by Bacillus thuringiensis mosquito-larvicidal Cry4Aa toxin Reviewed

    Yuri Shiraishi, Tomoya Shiozaki, Mami Asakura, Toru Ide, Tohru Hayakawa

    Applied Entomology and Zoology   57 ( 1 )   63 - 70   2022.2

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    Cry4Aa toxin produced by Bacillus thuringiensis subsp. israelensis exhibits specific toxicity to larvae of medically important mosquito genera. In the present study, we analyzed the characteristics of channel pores formed by recombinant Cry4Aa in a solvent-free planar lipid bilayer. Stable channel currents were observed in electrophysiologic measurements, and the single-channel conductance was 187 +/- 10 pS in symmetrical buffer containing 150 mM KCl. The channel pores formed by Cry4Aa were cation-selective, with an estimated P-K/P-Cl permeability ratio of 4.9. In addition, Cry4Aa channel pores exhibited apparent cation preference in the order Na+ > K+, Na+ > Ca2+, and K+ > Ca2+. Although the effect was limited, the cation preference of Cry4Aa channel pores seemed to be correlated with toxicity. Culex pipiens mosquito larvae reared in NaCl solution exhibited greater sensitivity to Cry4Aa, particularly early period after exposure. The presence of cations that preferentially translocate through Cry4Aa channel pores may facilitate excessive influx of water into the midgut cells, leading to colloid-osmotic lysis. Whereas CaCl2 had some effect on the mosquito-larvicidal activity of Cry4Aa, KCl had no effect. The effect of some cations may be mitigated by the variety of ion channels present on the midgut cell membrane.

    DOI: 10.1007/s13355-021-00762-6

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    Other Link: https://link.springer.com/article/10.1007/s13355-021-00762-6/fulltext.html

  • Bacillus thuringiensis Cry2Aa toxins bind to v-ATP synthase subunit A located on the midgut brush border membrane of Bombyx Mori Reviewed

    Miki Tanaka, Yuzuri Iwamoto, Tomoaki Kouya, Kenta Moriyama, Kazuya Tomimoto, Yasuyuki Shitomi, Tohru Hayakawa, Delwar M. Hossain, Shin-ichiro Asano, Masayuki Taniguchi, Masaaki Azuma, Hidetaka Hori

    Journal of Agricultural Research Pesticides and Biofertilizers   2 ( 5 )   1 - 13   2021.12

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  • A Lipid Bilayer Formed on a Hydrogel Bead for Single Ion Channel Recordings Reviewed International journal

    Minako Hirano, Daiki Yamamoto, Mami Asakura, Tohru Hayakawa, Shintaro Mise, Akinobu Matsumoto, Toru Ide

    Micromachines   11 ( 12 )   1070 - 1070   2020.12

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    Ion channel proteins play important roles in various cell functions, making them attractive drug targets. Artificial lipid bilayer recording is a technique used to measure the ion transport activities of channel proteins with high sensitivity and accuracy. However, the measurement efficiency is low. In order to improve the efficiency, we developed a method that allows us to form bilayers on a hydrogel bead and record channel currents promptly. We tested our system by measuring the activities of various types of channels, including gramicidin, alamethicin, α-hemolysin, a voltage-dependent anion channel 1 (VDAC1), a voltage- and calcium-activated large conductance potassium channel (BK channel), and a potassium channel from Streptomyces lividans (KcsA channel). We confirmed the ability for enhanced measurement efficiency and measurement system miniaturizion.

    DOI: 10.3390/mi11121070

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  • Channel-pore cation selectivity is a major determinant of Bacillus thuringiensis Cry46Ab mosquitocidal activity Reviewed International journal

    Tohru Hayakawa, Midoka Miyazaki, Syoya Harada, Mami Asakura, Toru Ide

    Applied Microbiology and Biotechnology   104 ( 20 )   8789 - 8799   2020.10

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    Cry46Ab from Bacillus thuringiensis TK-E6 is a new mosquitocidal toxin with an aerolysin-type architecture, and it is expected to be used as a novel bioinsecticide. Cry46Ab acts as a functional pore-forming toxin, and characteristics of the resulting channel pores, including ion selectivity, have been analyzed. However, the relationship between channel-pore ion selectivity and insecticidal activity remains to be elucidated. To clarify the effects of charged amino acid residues on the ion permeability of channel-pores and the resulting insecticidal activity, in the present study, we constructed Cry46Ab mutants in which a charged amino acid residue within a putative transmembrane β-hairpin region was replaced with an oppositely charged residue. Bioassays using Culex pipiens mosquito larvae revealed that the mosquitocidal activity was altered by the mutation. A K155E Cry46Ab mutant exhibited toxicity apparently higher than that of wild-type Cry46Ab, but the E159K and E163K mutants exhibited decreased toxicity. Ions selectivity measurements demonstrated that the channel pores formed by both wild-type and mutant Cry46Abs were cation selective, and their cation preference was also similar. However, the degree of cation selectivity was apparently higher in channel pores formed by the K155E mutant, and reduced selectivity was observed with the E159K and E163K mutants. Our data suggest that channel-pore cation selectivity is a major determinant of Cry46Ab mosquitocidal activity and that cation selectivity can be controlled via mutagenesis targeting the transmembrane β-hairpin region. KEY POINTS: • Cry46Ab mutants were constructed by targeting the putative transmembrane β-hairpin region. • Charged residues within the β-hairpin control the flux of ions through channel pores. • Channel-pore cation selectivity is correlated with insecticidal activity.

    DOI: 10.1007/s00253-020-10893-5

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    Other Link: https://link.springer.com/article/10.1007/s00253-020-10893-5/fulltext.html

  • Characterization of the channel-pores formed by Bacillus thuringiensis Cry46Ab toxin in planar lipid bilayers Reviewed

    Akira Sakakibara, So Takebe, Toru Ide, Tohru Hayakawa

    Applied Entomology and Zoology   54 ( 4 )   389 - 398   2019.11

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    Cry46Ab from Bacillus thuringiensis TK-E6 is a new mosquitocidal toxin with aerolysin-type architecture, and has been shown that co-administration of Cry46Ab with other mosquitocidal Cry toxins results in synergistic toxicity against Culex pipiens Coquillett (Diptera: Culicidae) mosquito larvae. Cry46Ab, therefore, is expected to find use in improving the insecticidal activity of B. thuringiensis-based bioinsecticides. In the present study, the mode of action of Cry46Ab was explored by single-channel measurements of Cry46Ab channel-pores. The single-channel conductances of channel-pores formed in planar lipid bilayers by Cry46Ab were determined to be 31.8 +/- 2.7 pS in 150 mM NaCl and 24.2 +/- 0.7 pS in 150 mM CaCl2. Ion-selectivity measurements revealed that the channel-pores formed by Cry46Ab were cation selective. The permeability ratio of K+ to Cl-was approximately 4, and the preferences for cations were K+ > Na+, K+ > Ca2+, and Ca2+ > Na+. A calcein release assay using liposomes suggested that Cry46Ab influences the integrity of membrane vesicles. Formation of cation-selective channel-pores has been observed with other insecticidal Cry toxins that have structures distinct from those of Cry46Ab; the capability of forming such pores may be a property required of insecticidal toxins.

    DOI: 10.1007/s13355-019-00635-z

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    Other Link: http://link.springer.com/article/10.1007/s13355-019-00635-z/fulltext.html

  • Glucose, some amino acids and a plant secondary metabolite, chlorogenic acid induce the secretion of a regulatory hormone, tachykinin-related peptide, from the silkworm midgut. Reviewed

    Yamagishi T, Endo H, Fukumura K, Nagata S, Hayakawa T, Adegawa S, Kasubuchi M, Sato R

    Peptides   106   21 - 27   2018.6

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  • Potency of the mosquitocidal Cry46Ab toxin produced using a 4AaCter-tag, which facilitates formation of protein inclusion bodies in Escherichia coli Reviewed

    Tomoaki Okazaki, Junya Ichinose, So Takebe, Toru Ide, Tohru Hayakawa

    Applied Entomology and Zoology   53 ( 1 )   67 - 73   2018.2

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    DOI: 10.1007/s13355-017-0529-5

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    Other Link: http://link.springer.com/content/pdf/10.1007/s13355-017-0529-5.pdf

  • Cry46Ab from Bacillus thuringiensis TK-E6 is a new mosquitocidal toxin with aerolysin-type architecture Reviewed

    Tohru Hayakawa, Akira Sakakibara, Sho Ueda, Yoshinao Azuma, Toru Ide, So Takebe

    Insect Biochemistry and Molecular Biology   87   100 - 106   2017.8

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    DOI: 10.1016/j.ibmb.2017.06.015

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  • Bacillus thuringiensis Cry11Ba works synergistically with Cry4Aa but not with Cry11Aa for toxicity against mosquito Culex pipiens (Diptera: Culicidae) larvae Reviewed

    Tohru Hayakawa, Naoya Yoneda, Kouji Okada, Ayuko Higaki, Mohammad Tofazzal Hossain Howlader, Toru Ide

    Applied Entomology and Zoology   52 ( 1 )   61 - 68   2017.2

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    DOI: 10.1007/s13355-016-0454-z

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  • Potency of insect-specific scorpion toxins on mosquito control using Bacillus thuringiensis Cry4Aa Reviewed

    Riku Matsumoto, Yoshitaka Shimizu, Mohammad Tofazzal Hossain Howlader, Maho Namba, Aya Iwamoto, Hiroshi Sakai, Tohru Hayakawa

    Journal of Bioscience and Bioengineering   117 ( 6 )   680 - 683   2014.6

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    DOI: 10.1016/j.jbiosc.2013.12.004

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  • Parasporin 1Ac2, a Novel Cytotoxic Crystal Protein Isolated from Bacillus thuringiensis B0462 Strain

    Shouta Kuroda, Anowara Begum, Mizue Saga, Akina Hirao, Eiichi Mizuki, Hiroshi Sakai, Tohru Hayakawa

    Current Microbiology   66 ( 5 )   475 - 480   2013.5

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    DOI: 10.1007/s00284-013-0301-1

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  • Efficient production of recombinant cystatin C using a peptide-tag, 4AaCter, that facilitates formation of insoluble protein inclusion bodies in Escherichia coli Reviewed

    Masahiro Hayashi, Shigehisa Iwamoto, Shinya Sato, Shigeo Sudo, Mari Takagi, Hiroshi Sakai, Tohru Hayakawa

    Protein Expression and Purification   88 ( 2 )   230 - 234   2013.4

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    DOI: 10.1016/j.pep.2013.01.011

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  • Mutational analyses of Cry protein block7 polypeptides that facilitate the formation of protein inclusion in Escherichia coli Reviewed

    Tohru Hayakawa, Yoshitaka Shimizu, Tatsuhiko Ishida, Hiroshi Sakai

    Applied Microbiology and Biotechnology   90 ( 6 )   1943 - 1951   2011.6

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    DOI: 10.1007/s00253-011-3216-4

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  • Novel strategy for protein production using a peptide tag derived from Bacillus thuringiensis Cry4Aa Reviewed

    Tohru Hayakawa, Shinya Sato, Shigehisa Iwamoto, Shigeo Sudo, Yoshiki Sakamoto, Takaaki Yamashita, Motoaki Uchida, Kenji Matsushima, Yohko Kashino, Hiroshi Sakai

    FEBS Journal   277 ( 13 )   2883 - 2891   2010.7

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    DOI: 10.1111/j.1742-4658.2010.07704.x

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  • Alanine Scanning Analyses of the Three Major Loops in Domain II of Bacillus thuringiensis Mosquitocidal Toxin Cry4Aa Reviewed

    Mohammad Tofazzal Hossain Howlader, Yasuhiro Kagawa, Ai Miyakawa, Ayaka Yamamoto, Tetsuya Taniguchi, Tohru Hayakawa, Hiroshi Sakai

    Applied and Environmental Microbiology   76 ( 3 )   860 - 865   2010.2

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    <title>ABSTRACT</title>

    Cry4Aa produced by
    <italic>Bacillus thuringiensis</italic>
    is a dipteran-specific toxin and is of great interest for developing a bioinsecticide to control mosquitoes. Therefore, it is very important to characterize the functional motif of Cry4Aa that is responsible for its mosquitocidal activity. In this study, to characterize a potential receptor binding site, namely, loops 1, 2, and 3 in domain II, we constructed a series of Cry4Aa mutants in which a residue in these three loops was replaced with alanine. A bioassay using
    <italic>Culex pipiens</italic>
    larvae revealed that replacement of some residues affected the mosquitocidal activity of Cry4Aa, but the effect was limited. This finding was partially inconsistent with previous results which suggested that replacement of the Cry4Aa loop 2 results in a significant loss of mosquitocidal activity. Therefore, we constructed additional mutants in which multiple (five or six) residues in loop 2 were replaced with alanine. Although the replacement of multiple residues also resulted in some decrease in mosquitocidal activity, the mutants still showed relatively high activity. Since the insecticidal spectrum of Cry4Aa is specific, Cry4Aa must have a specific receptor on the surface of the target tissue, and loss of binding to the receptor should result in a complete loss of mosquitocidal activity. Our results suggested that, unlike the receptor binding site of the well-characterized molecule Cry1, the receptor binding site of Cry4Aa is different from loops 1, 2, and 3 or that there are multiple binding sites that work cooperatively for receptor binding.

    DOI: 10.1128/aem.02175-09

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  • Biological properties of loop-replaced mutants of Bacillus thuringiensis mosquitocidal Cry4Aa Reviewed

    Mohammad Tofazzal Hossain Howlader, Yasuhiro Kagawa, Hiroshi Sakai, Tohru Hayakawa

    Journal of Bioscience and Bioengineering   108 ( 3 )   179 - 183   2009.9

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    DOI: 10.1016/j.jbiosc.2009.03.016

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  • Design and construction of a synthetic Bacillus thuringiensis Cry4Aa gene: Hyperexpression in Escherichia coli Reviewed

    Tohru Hayakawa, Mohammad Tofazzal Hossain Howlader, Masashi Yamagiwa, Hiroshi Sakai

    Applied Microbiology and Biotechnology   80 ( 6 )   1033 - 1037   2008.10

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    DOI: 10.1007/s00253-008-1560-9

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    Other Link: http://link.springer.com/article/10.1007/s00253-008-1560-9/fulltext.html

  • Parasporin-2Ab, a Newly Isolated Cytotoxic Crystal Protein from Bacillus thuringiensis Reviewed

    Tohru Hayakawa, Rie Kanagawa, Yosuke Kotani, Mayumi Kimura, Masashi Yamagiwa, Yoshiharu Yamane, So Takebe, Hiroshi Sakai

    Current Microbiology   55 ( 4 )   278 - 283   2007.10

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    DOI: 10.1007/s00284-006-0351-8

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  • Binding of Bacillus thuringiensis Cry1A toxins to brush border membrane vesicles of midgut from Cry1Ac susceptible and resistant Plutella xylostella Reviewed International journal

    Masahiro Higuchi, Kohsuke Haginoya, Takanori Yamazaki, Kazuhisa Miyamoto, Takahiro Katagiri, Kazuya Tomimoto, Yasuyuki Shitomi, Tohru Hayakawa, Ryoichi Sato, Hidetaka Hori

    Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology   147 ( 4 )   716 - 724   2007.8

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    Plutella xylostella strain resistant (PXR) to Bacillus thuringiensis Cry1Ac toxin was not killed at even more than 1000 microg Cry1Ac/g diet but killed by Cry1Ab at 0.5 microg/g diet. In contrast, susceptible strain (PXS) was killed by Cry1Ac at 1 microg/g diet. Cy3-labeld Cry1A(s) binding to brush border membrane vesicles (BBMV) prepared from both strains were analyzed with direct binding assay. The Kd value of Cry1Aa to both BBMV was almost identical: 213.2 and 205.8 nM, and 263.5 and 265.0 nM for Cry1Ac. The highest Kd values were in Cry1Ab which showed most effective insecticidal activity in PXS and PXR, 2126 and 2463 nM, respectively. These results clearly showed that the BBMV from PXR and PXS could equally bind to Cry1Ac. The binding between BBMV and Cy3-labeled Cry1Ac was inhibited only by anti-175 kDa cadherin-like protein (CadLP) and -252 kDa protein antisera, but not by anti-120 kDa aminopeptidase. This supports that resistance in PXR resulted from the abortion of pore formation after the binding of Cry1Ac to the BBMV. And furthermore, the importance of 175K CadLP and P252 proteins in those bindings was suggested. We briefly discuss possible mechanisms of the resistance.

    DOI: 10.1016/j.cbpb.2007.04.013

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  • Flexibility and strictness in functional replacement of domain III of cry insecticidal proteins from Bacillus thuringiensis Reviewed

    Hiroshi Sakai, Mohammad Tofazzal Hossain Howlader, Yumiko Ishida, Akiko Nakaguchi, Keiko Oka, Kouji Ohbayashi, Masashi Yamagiwa, Tohru Hayakawa

    Journal of Bioscience and Bioengineering   103 ( 4 )   381 - 383   2007.4

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    DOI: 10.1263/jbb.103.381

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  • Histochemical analysis of Bacillus thuringiensis CrylA toxin binding to midgut epithelial cells of Bombyx mori Reviewed

    Delwar M. Hossain, Tohru Hayakawa, Yasuyuki Shitomi, Kimiko Itoh, Toshiaki Mitsui, Ryoichi Sato, Hidetaka Hori

    Pesticide Biochemistry and Physiology   87 ( 1 )   30 - 38   2007.1

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    DOI: 10.1016/j.pestbp.2006.01.011

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  • Pronase digestion of brush border membrane-bound Cry1Aa shows that almost the whole activated Cry1Aa molecule penetrates into the membrane Reviewed

    Kazuya Tomimoto, Tohru Hayakawa, Hidetaka Hori

    Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology   144 ( 4 )   413 - 422   2006.8

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    DOI: 10.1016/j.cbpb.2006.04.013

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  • Plasmodiophora brassicae-induced Cell Death and Medium Alkalization in Clubroot-resistant Cultured Roots of Brassica rapa Reviewed

    H. Takahashi, T. Ishikawa, M. Kaido, K. Takita, T. Hayakawa, K. Okazaki, K. Itoh, T. Mitsui, H. Hori

    Journal of Phytopathology   154 ( 3 )   156 - 162   2006.3

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    DOI: 10.1111/j.1439-0434.2006.01076.x

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  • A Novel 96-kDa Aminopeptidase Localized on Epithelial Cell Membranes of Bombyx mori Midgut, Which Binds to Cry1Ac Toxin of Bacillus thuringiensis Reviewed International journal

    Yasuyuki Shitomi, Tohru Hayakawa, Delwar M. Hossain, Masahiro Higuchi, Kazuhisa Miyamoto, Kazuko Nakanishi, Ryoichi Sato, Hidetaka Hori

    The Journal of Biochemistry   139 ( 2 )   223 - 233   2006.2

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    Proteins in the brush border membrane (BBM) of the midgut binding to the insecticidal Cry1Ac toxin from Bacillus thuringiensis were investigated to examine the lower sensitivity of Bombyx mori to Cry1Ac, and new aminopeptidase N that bound to Cry1Ac was discovered. DEAE chromatography of Triton X-100-soluble BBM proteins from the midgut revealed 96-kDa aminopeptidase that bound to Cry1Ac. The enzyme was purified to homogeneity and estimated to be a 96.4-kDa molecule on a silver-stained SDS-PAGE gel. However, the native protein was eluted as a single peak corresponding to approximately 190-kDa on gel filtration and gave a single band on native PAGE. The enzyme was determined to be an aminopeptidase N (APN96) from its substrate specificity. Antiserum to class 3 B. mori APN (BmAPN3) recognized APN96, but peptide mass fingerprinting revealed that 54% of the amino acids of matched peptides were identical to those of BmAPN3, suggesting that APN96 was a novel isoform of the APN3 family. On ligand blots, APN96 bound to Cry1Ac but not Cry1Aa or Cry1Ab, and the interaction was inhibited by GalNAc. K(D) of the APN96-Cry1Ac interaction was determined to be 1.83 +/- 0.95 microM. The lectin binding assay suggested that APN96 had an N-linked bi-antennal oligosaccharide or an O-linked mucin type one. The role of APN96 was discussed in relation to the insensitivity of B. mori to Cry1Ac.

    DOI: 10.1093/jb/mvj024

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  • Bacillus thuringiensis Cry1Ab, but not Cry1Aa or Cry1Ac, disrupts liposomes Reviewed

    Taisuke Kato, Masahiro Higuchi, Ryo Endo, Takeshi Maruyama, Kousuke Haginoya, Yasuyuki Shitomi, Tohru Hayakawa, Toshiaki Mitsui, Ryoichi Sato, Hidetaka Hori

    Pesticide Biochemistry and Physiology   84 ( 1 )   1 - 9   2006.1

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    DOI: 10.1016/j.pestbp.2005.02.001

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  • Localization of a novel 252-kDa plasma membrane protein that binds Cry1A toxins in the midgut epithelia of Bombyx mori Reviewed

    Delwer M. Hossain, Yasuyuki Shitomi, Yohei Nanjo, Daisuke Takano, Tadayuki Nishiumi, Tohru Hayakawa, Toshiaki Mitsui, Ryoichi Sato, Hidetaka Hori

    Applied Entomology and Zoology   40 ( 1 )   125 - 135   2005

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    DOI: 10.1303/aez.2005.125

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  • GalNAc pretreatment inhibits trapping ofBacillus thuringiensisCry1Ac on the peritrophic membrane ofBombyx mori Reviewed

    Tohru Hayakawa, Yasuyuki Shitomi, Kazuhisa Miyamoto, Hidetaka Hori

    FEBS Letters   576 ( 3 )   331 - 335   2004.10

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    DOI: 10.1016/j.febslet.2004.09.029

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  • Characterization of a Novel Plasma Membrane Protein, Expressed in the Midgut Epithelia of Bombyx mori , That Binds to Cry1A Toxins Reviewed International journal

    Delwar M. Hossain, Yasuyuki Shitomi, Kenta Moriyama, Masahiro Higuchi, Tohru Hayakawa, Toshiaki Mitsui, Ryoichi Sato, Hidetaka Hori

    Applied and Environmental Microbiology   70 ( 8 )   4604 - 4612   2004.8

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    <title>ABSTRACT</title>

    We describe the properties of a novel 252-kDa protein (P252) isolated from brush border membranes of
    <italic>Bombyx mori</italic>
    . P252 was found in a Triton X-100-soluble brush border membrane vesicle fraction, suggesting that it may be a component of the midgut epithelial cell membrane. P252 was purified to homogeneity, and the amino acid sequence of two internal peptides was determined, but neither of the peptides matched protein sequences in the available databases. The apparent molecular mass of the purified protein was estimated by denaturing gel electrophoresis to be 252 kDa, and it migrated as a single band on native gels. However, gel filtration chromatography indicated an apparent mass of 985 kDa, suggesting that P252 may exist as a homo-oligomer. The associations of P252 with Cry1Aa, Cry1Ab, and Cry1Ac were specific, and
    <italic>
    K
    d
    </italic>
    constants were determined to be 28.9, 178.5, and 20.0 nM, respectively. A heterologous competition assay was also done. P252 did not exhibit Leu-pNA hydrolysis activity, and binding to the Cry1A toxins was not inhibited by GalNAc. Binding assays of P252 with various lectins indicated the presence of three antennal N-linked high-mannose-type as well as O-linked mucin-type sugar side chains. While the function of P252 is not yet clear, we propose that it may function with Cry1A toxins during the insecticidal response and/or Cry toxin resistance mechanism.

    DOI: 10.1128/aem.70.8.4604-4612.2004

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  • Transgenic tobacco transformed with theTrichopusia niGranulovirusEnhancingene affects insect development Reviewed

    Tohru Hayakawa, Yoshifumi Hashimoto, Masashi Mori, Masanori Kaido, Eiichi Shimojo, Iwao Furusawa, Robert R. Granados

    Biocontrol Science and Technology   14 ( 2 )   211 - 214   2004.3

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    DOI: 10.1080/0958315031000151710

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  • Increase in Indole-3-acetic Acid(IAA) level and Nitrilase Activity in Turnips Induced by Plasmodiophora brassicae Infection. Reviewed

    Tsutomu UGAJIN, Kazuo TAKITA, Hideyuki TAKAHASHI, Satoko MURAOKA, Taketoshi TADA, Toshiaki MITSUI, Tohru HAYAKAWA, Takuji OHYAMA, Hidetaka HORI

    Plant Biotechnology   20 ( 3 )   215 - 220   2003

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Japanese Society for Plant Cell and Molecular Biology  

    DOI: 10.5511/plantbiotechnology.20.215

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  • Comparative study on capability of binding of BBMV proteins from Plutella xylostella which were highly resistant and susceptible to Cry1Ac using Bacillus thuringiensis Cry1A toxins

    Higuchi Masahiro, Maruyama Takeshi, Endo Ryo, Shitomi Yasuyuki, Hayakawa Tohru, Mitsui Toshiaki, Sato Ryoichi, Hori Hidetaka

    Abstracts of the Annual Meeting, The Japanese Society of Sericultural Science   jsss72   66 - 66   2002

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    CHAPS-soluble proteins from BBMV of Plutella xylostella which were highly resistant and susceptible to Cry1Ac of Bacillus thuringiensis were used to determine the capability of binding with Cry1A toxins. Both ligand and western blot analyses with the proteins and Cry1A toxins showed that major three 120, 110 and 100 kDa proteins bound with Cry1Aa and Ac, but not with Cry1Ab. Furthermore, the proteins were positive with anti aminopeptidase N antibody and the intensity and pattern of the binding were almost the same, respectively in the both straihs. Cry1Aa and Ac were shown to bind with the proteins at about 0.7 ng toxin/mm2 membrane/10 min in both the strains using plasmon resonance. Their binding curves were almost the same each other. Cry1Ab, however, was not shown to bind with the BBMV proteins in both the strains.

    DOI: 10.11416/jsss.jsss72.0.66.0

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  • Novel aminopeptidase of Bombyx mori BBMV, which was negative against anti 120 kDa APN antibody and specifically bound to Cry1Ac of Bacillus thuringiensis

    Shitomi Yasuyuki, Higuchi Masahiro, Hayakawa Tohru, Miyamoto Kazuhisa, Mitsui Toshiaki, Sato Ryoichi, Hori Hidetaka

    Abstracts of the Annual Meeting, The Japanese Society of Sericultural Science   jsss72   64 - 64   2002

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    A hundred twenty kDa aminopeptidase N (APN120) from Bombyx mori BBM has been thought to be a candidate for the receptor of Bacillus thuringiensis Cry1Aa and Cry1Ac toxins. Ligand blot analysis showed that Cry1Aa and Cry1Ac bound to not only APN120 but also APN110 and APN100. Along with these APN proteins, we found 90 kDa APN like protein (APN90) having significant APN activity but negative to anti APN120 antibody. The APN was purified with DEAE Sepharose and Sephacryl S300 chromatography and at least seven APN-like proteins were found. In ligand blot analysis, APN90 was shown to specifically bind to Cry1Ac but neither Cry1Aa nor Cry1Ab. Here we present interesting and novel properties of purified APN90 and we also briefly discuss the role of it.

    DOI: 10.11416/jsss.jsss72.0.64.0

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  • Tandem repetition of baculovirus ie1 promoter results in upregulation of transcription Reviewed

    K. Kojima, T. Hayakawa, S. Asano, H. Bando

    Archives of Virology   146 ( 7 )   1407 - 1414   2001.7

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    DOI: 10.1007/s007050170101

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  • Sequence Analysis of the Plutella xylostella Granulovirus Genome Reviewed

    Yoshifumi Hashimoto, Tohru Hayakawa, Yasumasa Ueno, Tomonori Fujita, Yoshitaka Sano, Tsuguo Matsumoto

    Virology   275 ( 2 )   358 - 372   2000.9

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    DOI: 10.1006/viro.2000.0530

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  • Analysis of proteins encoded in the bipartite genome of a new type of parvo-like virus isolated from silkworm — structural protein with DNA polymerase motif Reviewed

    Tohru Hayakawa, Katsura Kojima, Kiichirou Nonaka, Masao Nakagaki, Ken Sahara, Shin-ichiro Asano, Toshihiko Iizuka, Hisanori Bando

    Virus Research   66 ( 1 )   101 - 108   2000.1

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    DOI: 10.1016/s0168-1702(99)00129-x

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  • Enhancement of baculovirus infection in Spodoptera exigua (Lepidoptera: Noctuidae) larvae with Autographa californica nucleopolyhedrovirus or Nicotiana tabacum engineered with a granulovirus enhancin gene. Reviewed

    Tohru Hayakawa, Ei-ichi Shimojo, Masashi Mori, Masanori Kaido, Iwao Furusawa, Seiji Miyata, Yoshitaka Sano, Tsuguo Matsumoto, Yoshifumi Hashimoto, Robert R. Granados

    Applied Entomology and Zoology   35 ( 1 )   163 - 170   2000

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    DOI: 10.1303/aez.2000.163

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  • Physical map of a Plutella xylostella granulovirus genome. Reviewed

    Yoshifumi Hashimoto, Kana Hayashi, Tohru Hayakawa, Yasumasa Ueno, Ei-ichi Shimojo, Atsushi Kondo, Minoru Miyasono, Yoshitaka Sano, Tsuguo Matsumoto, Robert R. Granados

    Applied Entomology and Zoology   35 ( 1 )   45 - 51   2000

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    DOI: 10.1303/aez.2000.45

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  • Identification, sequence analysis and phylogeny of the lef-2 gene of Helicoverpa armigera single-nucleocapsid baculovirus Reviewed

    Xinwen Chen, Wilfred F.J IJkel, Cliff Dominy, Paolo Marinho de Andrade Zanotto, Yoshifumi Hashimoto, Ouriel Faktor, Tohru Hayakawa, Chung-Hsiung Wang, Arumagam Prekumar, Sinnakaruppan Mathavan, Peter J Krell, Zhihong Hu, Just M Vlak

    Virus Research   65 ( 1 )   21 - 32   1999.12

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    DOI: 10.1016/s0168-1702(99)00097-0

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  • Sequence Analysis of the Xestia c-nigrum Granulovirus Genome Reviewed

    Tohru Hayakawa, Rinkei Ko, Kazuhiro Okano, Su-Il Seong, Chie Goto, Susumu Maeda

    Virology   262 ( 2 )   277 - 297   1999.9

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    DOI: 10.1006/viro.1999.9894

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  • Genome organization of Xestia c-nigrum granulovirus Reviewed

    Chie Goto, Tohru Hayakawa, Susumu Maeda

    Virus Genes   16 ( 2 )   199 - 210   1998

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    DOI: 10.1023/a:1007972108026

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  • Detection of replicative intermediate with closed terminus of Bombyx densonucleosis virus Reviewed

    T. Hayakawa, S. Asano, K. Sahara, T. Iizuka, H. Bando

    Archives of Virology   142 ( 2 )   393 - 399   1997.2

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    DOI: 10.1007/s007050050085

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  • Detection of the silkworm-pathogenic virus genomes by PCR. Reviewed

    KAGEYASU SEIJI, HAYAKAWA TOHRU, ISAWA HARUHIKO, ASANO SHINICHIRO, SAHARA KEN, IIZUKA TOSHIHIKO, BANDO HISANORI

    The Journal of Sericultural Science of Japan   66 ( 6 )   477 - 483   1997

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    Language:Japanese   Publisher:The Japanese Society of Sericultural Science  

    The five viruses, Bombyx mori densonucleosis virus type 1 (BmDNV-1), -type 2 (BmDNV-2), Bombyx mori nuclear polyhedrosis virus (BmDPV), Bombyx mori cytoplasmic polyhedrosis virus (BmCPV), and Infectious flacherie virus (IFV), are the agents causing fetal disease of the silkworm. The aim of this study is to establish a simple and highly sensitive PCR system for detection of all the viruses. A combination of the RT-PCR and the nested PCR was found to be effective to amplify DNA and/or RNA virus genome sequences in a reaction maintaining high sensitivity and specificity. In this report, the primer design and the condition of the PCR for the detection of all the viruses are described.

    DOI: 10.11416/kontyushigen1930.66.477

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  • Physical mapping and identification of interspersed homologous sequences in the Trichoplusia ni granulosis virus genome Reviewed

    Y. Hashimoto, K. Hayashi, Y. Okuno, T. Hayakawa, A. Saimoto, R. R. Granados, T. Matsumoto

    Journal of General Virology   77 ( 3 )   555 - 563   1996.3

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    DOI: 10.1099/0022-1317-77-3-555

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  • Analysis of the genetic information of a DNA segment of a new virus from silkworm Reviewed

    H. Bando, T. Hayakawa, S. Asano, K. Sahara, M. Nakagaki, T. Iizuka

    Archives of Virology   140 ( 6 )   1147 - 1155   1995.6

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    DOI: 10.1007/bf01315423

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  • Physical Mapping of Bombyx mori Nuclear Polyhedrosis Virus Strain D1 : Identification of Novel Interspersed Homologous Regions Reviewed

    Yoshifumi HASHIMOTO, Yoichi KANAMORI, Tohru HAYAKAWA, Yasuaki KATAYAMA, G. Shizuo KAMITA, Susumu MAEDA, Tsuguo MATSUMOTO

    Applied Entomology and Zoology   29 ( 3 )   442 - 448   1994

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    DOI: 10.1303/aez.29.442

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Books

  • カイコの科学

    ( Role: Contributor ,  第4章 カイコの病気から学ぶ、4.4 病原細菌が放つ殺虫性タンパク質)

    朝倉書店  2020.7 

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  • 最新昆虫病理学

    早川徹, 酒井裕( Role: Contributor ,  第10章 昆虫病理学の展開、4 Bacillus thuringiensisの開発と利用)

    講談社  2014.2 

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  • 応用生物学入門

    ( Role: Contributor ,  第一編 環境と個体の生物科学 第4章 微生物にみる環境適応)

    オーム社  2010.12  ( ISBN:9784274209741

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  • 分子昆虫学-ポストゲノムの昆虫研究-(Molecular Entomology-Post-genomic Insect Sciences-)

    ( Role: Contributor ,  第5章 昆虫微生物相互作用、5.1. 病理、5.1.1. 細菌)

    共立出版  2009.8 

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  • 昆虫テクノロジー研究とその産業利用 (Insects: useful resources for new industrial products)

    早川徹, 堀秀隆( Role: Contributor ,  第4章 害虫制御技術等農業現場への応用 3節Bacillus thuringiensisの殺虫蛋白質の科学と応用)

    シーエムシー出版  2005.6  ( ISBN:4882315041

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  • Bacillus thuringiensis 殺虫蛋白質の科学-環境保全型生物農薬から抗ガン活性まで-

    ( Role: Contributor ,  2章5節(pp66-68)、6章4節(pp183-189)、5節(pp190-191))

    アイピーシー  2005.2  ( ISBN:4901493531

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  • 昆虫を殺すウイルスの話

    ( Role: Sole author)

    新潟日報事業社  2003.2  ( ISBN:4888629560

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  • 微生物からのメッセージ

    福田雅夫, 大山卓爾, 堀秀隆, 小島誠, 早川徹( Role: Joint author ,  第4章 ウイルスの不思議)

    エンタプライズ  2001.3  ( ISBN:478252059X

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MISC

  • Development of efficient system to improve mosquitocidal toxins of soil bacteria

    Annual report of the Okayama foundation for science and technology   32   40 - 42   2023.10

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  • 環境に優しく持続利用可能な微生物殺蚊剤を開発するための分子基盤

    早川 徹

    研究レポート集2022, 公益財団法人八雲環境科学振興財団   23   104 - 109   2022.11

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  • 蚊を殺すトキシン由来のポリペプチドを利用して効率的なタンパク質の生産系を構築する

    早川 徹

    昆虫と自然   51 ( 7 )   41 - 42   2016

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  • Bacillus thuringiensis TK-E6が産生する非3-ドメイン型Cryタンパク質の殺ボウフラ活性

    根来綾子, 江草佳務, 上林智仁, 早崎君江, 岡本成平, 東慶直, 東慶直, 早川徹, 武部聡, 武部聡

    日本農芸化学会大会講演要旨集(Web)   2015   2015

  • Bacillus thuringiensis由来のタンパク質結晶化因子4AaCterタグを用いた殺虫タンパク質の生産

    杉森勇太, 佐藤一樹, 石田達彦, 早川徹, 酒井裕, 東慶直, 武部聡

    日本農芸化学会大会講演要旨集   2011   2011

  • 細胞損傷蛋白質パラスポリンを通して見るCryタンパク質の可能性

    早川徹, 酒井裕

    蚕糸昆虫バイオテック (SANSHI-KONCHU BIOTEC)   77 ( 3 )   205 - 210   2008

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    Authorship:Lead author, Corresponding author   Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:社団法人 日本蚕糸学会  

    DOI: 10.11416/konchubiotec.77.3_205

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  • Expression of Bombyx mori Aminopeptidase N on Plasma Membrane of Cultured Insect Cells and Analysis of Its Receptor Function for Insecticidal Cry Toxins

    Noguchi Rieko, Ishikawa Toshiki, Haginoya Kohsuke, Shitomi Yasuyuki, Sato Ryoichi, Hayakawa Tohru, Hori Hidetaka

    Bulletin of the Faculty of Agriculture, Niigata University   第60巻 ( 1号 )   73 - 81   2007

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    Aminopeptidase N(APN) localizing on the apical membrane of midgut epithelial cells is one of the plausible candidate of the receptor proteins for Bacillus thuringiensis Cry1Aa toxin which specifically kills lepidopteran insects. However, comprehensive evidences to address above possibility have not been established yet. We tried to express the APN1, BmAPN1, onto plasma membrane of cultured insect cells to investigate the interaction with Cry1Aa. Gene expression system was constructed with High five cultured insect cells and baculovirus expression system. On 48 h after the infection of the cells with gene modified baculovirus, 110 kDa BmAPN1 was expressed on the cell membranes. Aminopeptidase activity was ten times higher than that of non-infected cultured cells. The recombinant BmAPN1 was the same size as native one localizing on the brush border membrane of midgut epithelial cells. The transformed cells expressing BmAPN1 is a good system for the investigation of interaction between APN and Cry1Aa toxin.

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    Other Link: http://hdl.handle.net/10191/5041

  • Quantification of Aluminum Content in the Compost Made with Sludge Wasted from a Bean Curd Factory

    Noguchi Rieko, Mohamad Monjil S., Kohya Hiroe, Miura Mizuho, Ono Hironori, Takahashi Hitomi, Haginoya Kohsuke, Hayakawa Tohru, Hori Hidetaka

    Bulletin of the Faculty of Agriculture, Niigata University   60 ( 1 )   47 - 51   2007

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    Wasted sludge from a bean curd factory was mixed with newspaper chips cut (12 mm ×3 mm) and aerated right after the placement of the mixture into a fermenter. The sludge was mixed with newspaper chips at 15% (w/w) and composted under continuous aeration at 80 L/min/m2 bottom area of the fermenter. Hereafter we called the compost as paper-compost. The resulted paper-compost showed no inhibitory effect in germination of the komatsuna, Brassica nappas seeds and increased thereafter growth of them. On the other hand, the application of chemical fertilizer at the same amount of nitrogen content as that of paper-compost showed almost no growth of the plantlets. Generally, polyaluminum chlorides were added to the wasted water in active sludge sewer system to coagulate the excess amount of sludge, therefore, there is a possibility that the Al to remain after even the completion of composting, then the aluminum contents in the compost was evaluated with an atomic absorption spectrophotometer. The content in the compost was 160 mg/kg compost dried. On the other hand, the aluminum contents in wasted sludge and newspaper which were used to make the compost were 110 and 150 mg/kg, respectively. Thus, the aluminum in the composts was thought to be derived from those newspapers and active sludge. At least, polyaluminum chloride used to coagulate the excess sludge was not seemed to remain in the compost.

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    Other Link: http://agriknowledge.affrc.go.jp/RN/2010742738

  • Loading of Fura-2 into Liquid Organ Cultured Adventitious Root of Turnip (Brassica rapa L.) Resistant to Clubroot Pathogen Plasmodiophora brassicae and Determination of [Ca2+]cyt

    Takahashi Hideyuki, Ishikawa Toshiki, Hayakawa Tohru, Itoh Kimiko, Mitsui Toshiaki, Hori Hidetaka

    Bulletin of the Faculty of Agriculture, Niigata University   60 ( 1 )   61 - 66   2007

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    Our previous study using liquid organ cultured adventitious roots from turnip (Brassica rapa L.) showed that Ca2+ is required for induction of defense responses in the cultured roots on the treatment with Plasmodiophora brassicae resting spores (Takahashi et al., 2006). To evaluate change in [Ca2+]cyt in cultured root cells on contact with the spores, acetoxymethyl ester derivative of Fura-2 (Fura-2/AM) was loaded into the roots. When ionophore A23187 was treated with Ca2+ simultaneously, the Fura-2 fluorescence ratio that represents relative [Ca2+]cyt increased promptly, showing that the Fura-2/AM system is suitable to evaluate [Ca2+]cyt change in cultured root cells in a second range. Applicability of this method for studies on Ca2+ fluctuation against various extracellular stimuli was supported by observations that treatment with mannitol or NaCl also immediately increased the Fura-2 ratio. When the Fura-2/AM loaded roots were treated with resting spores, no [Ca2+]cyt change was observed during 500 second but when treated with spores pre-incubated with germination-enhancing suspension (GES), a slight but reproducible increase in [Ca2+]cyt was observed. We conclude that although further analysis is needed, the Fura-2/AM system will contribute to revealing the Ca2+ involvement in clubroot-resistance response.

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    Other Link: http://agriknowledge.affrc.go.jp/RN/2010742740

  • The mechanism of resistance to Cry1A toxins analysis of the interaction between Cry1A and brush border membrane and peritrophic membrane of Bombyx mori. Reviewed

    Hayakawa T, Hossain DM, Shitomi Y, Sato R, Hori H

    Proceedings international conference on Biopesticides 4, Chiang Mai, Thailand. (Uruyakorn Chansang, Duangkhae Sitthicharoenchai, Mir S. Mulla eds)   81 - 89   2006

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  • Detection of membrane-inserted region of Cry1Aa of Bacullus thuringiensis Reviewed

    Tomimoto K, Hayakawa T, Mitsui T, Hori H

    Biotechnology of Bacillus thuringiensis (Ngo Dinh Binh, Ray J. Akhurst, Donald H. Dean eds)   5   119 - 124   2005

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  • Preparation of Stable Liposomes Using Sucrose Density Gradient Centrifugation and Their Interaction with Insecticidal Cry1A Toxins of Bacillus thuringiensis

    HAGINOYA Kohsuke, KATO Taisuke, HIGUCHI Masahiro, SHITOMI Yasuyuki, ASAKURA Tsuyoshi, HAYAKAWA Tohru, MITSUI Toshiaki, HORI Hidetaka

    Bulletin of the Faculty of Agriculture, Niigata University   57 ( 2 )   115 - 120   2005

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    Other Link: http://agriknowledge.affrc.go.jp/RN/2010711999

  • Allergenic assessment of Cry1Aa using Rat digestive juice and mast cells. Reviewed

    Egawa Y, Okuyama K, Hara T, Tomimoto K, Hayakawa T, Hori H

    Biotechnology of Bacillus thuringiensis(Ngo Dinh Binh, Ray J. Akhurst, Donald H. Dean eds)   5   389 - 394   2005

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  • A novel 252kDa protein from BBMV of Bombyx mori, which bound with Cry1A toxins but did not bind with anti-APN or BtR175 antibodies. Reviewed

    Hossain DM, Shitomi Y, Moriyama K, Higuchi M, Hayakawa T, Sato R, Hori H

    Biotechnology of Bacillus thuringiensis (Ngo Dinh Binh, Ray J. Akhurst, Donald H. Dean eds)   5   223 - 228   2005

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  • Characterization of Bombyx mori AP96 which binds with Cry1Ac. Reviewed

    Shitomi Y, Moriyama K, Hossain DM, Higuchi M, Hayakawa T, Miyamoto K, Mitsui T, Nakanishi K, Sato R, Hori H

    Biotechnology of Bacillus thuringiensis (Ngo Dinh Binh, Ray J. Akhurst, Donald H. Dean eds)   5   187 - 194   2005

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  • Proteomic approach for comparative analysis of midgut proteins from Plutella xylostella that is highly resistant to Cry1Ac toxin. Reviewed

    Ahmad M, Maruyama T, Higuchi M, Hayakawa T, Mitsui T, Sato R, Hori H

    Biotechnology of Bacillus thuringiensis (Ngo Dinh Binh, Ray J. Akhurst, Donald H. Dean eds)   5   177 - 182   2005

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  • Novel binding proteins for Cry1A of Bacillus thuringiensis toxins and complicated killing mechanism Reviewed

    Hayakawa T, Shitomi Y, Hossain DM, Higuchi M, Sato R, Maruyama T, Miyamoto K, Hori H

    Biotechnology of Bacillus thuringiensis (Ngo Dinh Binh, Ray J. Akhurst, Donald H. Dean eds)   5   163 - 176   2005

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  • Differential Extraction of the Proteins Localizing on Cell Membranes of Midgut from Bombyx mori with Triton X-114

    Bulletin of the Faculty of Agriculture,Niigata University   55 ( 2 )   133 - 141   2003

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  • Activity of Phosphatidylinositol/UDP-GlcNAc:GlcNAc Transferase in Midgut Tissue of Bombyx mori

    Bulletin of the Faculty of Agriculture,Niigata University   55 ( 2 )   123 - 131   2003

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  • Enhancement of Germination of Spores from Obligatory Plant Pathogen,Plasmodiophora brassicae Causing Clubroot Disease

    OGAWA Satoshi, TAKAHASHI Hideyuki, HAYAKAWA Tohru

    Bulletin of the Faculty of Agriculture, Niigata University   54 ( 1 )   35 - 43   2001.8

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    CiNii Article

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  • Patterns of genome organization and content in lepidopteran baculoviruses Reviewed

    T Hayakawa, GF Rohrmann, Y Hashimoto

    VIROLOGY   278 ( 1 )   1 - 12   2000.12

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    Authorship:Lead author   Language:English   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:ACADEMIC PRESS INC  

    DOI: 10.1006/viro.2000.0668

    Web of Science

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  • Bacullus thuringiensis specific to scarabaeid beeltes.

    Hori H, Kumaraswami NS, Hayakawa T, Mitsui T

    Entomologia Sinica   7 ( 4 )   359 - 387   2000

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  • Bacillus thuringiensis specific to scarabaeid beetles: A review

    Hidetaka Hori, N. Selvamuthu Kumaraswami, Tohru Hayakawa, Toshiaki Mitsui

    Insect Science   7 ( 4 )   359 - 376   2000

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    Abstract Since the first report of Bacillus sotto by Ishiwata in 1901, thousands of related papers about Bacillus thuringiensis have been documented. In the field of biocontrol of insect pests by this bacterium, after the initial discovery of several B. thuringiensis isolates specific for lepidopteran insects, the isolation of B. thuringiensis israelensis, specific to dipteran larvae by Goldberg and Margalit, and B. thuringiensis tenebrionis, specific to some group of coleopteran insects by Krieg et al. were epoch making advances. In 1992, Ohba et al. isolated B. thuringiensis ja ponensis strain Buibui, which was specific to only scarabaeid larvae. This isolate is the main target of our discussion in this review. These discoveries by which not only B. thuringiensis sciences, but also applied biological control strategies have been enriched, which inspirit us to screen novel isolates. On the other hand, the fields of molecular biology and biochemistry studies on the structural elucidation of toxin proteins and mechanism of action have also tremendously progressed. But the complete mechanism has yet to be solved. For instance, interaction between receptor proteins locating on the plasma membrane of insect midgut epithelial cells and insecticidal proteins has not been fully sketched- In a way, this field is still in chaos. Addressing these exciting and enigmatic subjects will eventually lead to the construction of sustainable agriculture in the 21st century. © 2017 Wiley. All rights reserved.

    DOI: 10.1111/j.1744-7917.2000.tb00235.x

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Presentations

  • Mutational analysis of the mosquitocidal Mpp46Ab transmembrane β-hairpin region

    Kiyotaka Shimokawara, Ryoya Kodani, Minako Hirano, Toru Ide, Tohru Hayakawa

    2024.11.29 

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    Event date: 2024.11.27 - 2024.11.29

    Language:Japanese   Presentation type:Poster presentation  

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  • Potency of agarose-gel supported lipid bilayers for electrophysiological analysis of channel-pores formed by Bacillus thuringiensis insecticidal proteins.

    Tsubasa Okuda, Tomoya Takeuchi, Mami Asakura, Minako Hirano, Toru Ide, Tohru Hayakawa

    2024.11.29 

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    Event date: 2024.11.27 - 2024.11.29

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  • Insecticidal synergism between mosquito-larvicidal Mpp46Ab and Cry4Aa from Bacillus thuringiensis

    Tohru Hayakawa, Syun Yamaoka, Mami Asakura, Toru Ide

    2024.11.28 

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    Event date: 2024.11.27 - 2024.11.29

    Language:Japanese   Presentation type:Poster presentation  

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  • Simple procedure to facilitate analysis of the channel-pores formed by insecticidal Cry toxins

    Tsubasa Okuda, Tomoya Takeuchi, Minako Hirano, Toru Ide, Tohru Hayakawa

    2023.12.7 

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    Event date: 2023.12.6 - 2023.12.8

    Language:Japanese   Presentation type:Poster presentation  

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  • Structural insight of the channel-pores formed by mosquito-larvicidal Mpp46Ab toxin

    Tohru Hayakawa, Kiara Sumioku, Manami Imada, Mami Asakura, Toru Ide

    2023.12.6 

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    Event date: 2023.12.6 - 2023.12.8

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  • Improvement of Bacillus thuringiensis mosqitocidal Cry46Ab toxin by introducing mutation

    Tohru Hayakawa, Kiara Sumioku, Midoka Miyazaki, Mami Asakura, Toru Ide

    2022.11.30 

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    Event date: 2022.11.30 - 2022.12.2

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  • Bt菌Cry46Abトキシンの小孔形成とその殺虫活性

    宮崎美登香, 早川徹, 井出徹

    第59回生物物理学会年会  2021 

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    Event date: 2021.11.25 - 2021.11.27

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  • 殺蚊トキシンCry46Abの小孔形成と殺虫活性

    早川徹, 宮﨑美登香, 榊原暁, 原田翔也, 朝倉真実, 井出徹

    第42回日本分子生物学会年会  2019 

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    Event date: 2019.12.3 - 2019.12.6

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  • 非常に強い殺蚊活性を示すCry11Baトキシンの作用機構

    新谷彩子, 白石優里, 汐崎友哉, 井出徹, 早川徹

    第42回日本分子生物学会年会  2019 

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    Event date: 2019.12.3 - 2019.12.6

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  • 殺蚊トキシンCry4Aaが形成するチャネルポアの性状

    白石優里, 小薗寛人, 宮﨑美登香, 新谷彩子, 井出徹, 早川徹

    第42回日本分子生物学会年会  2019 

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    Event date: 2019.12.3 - 2019.12.6

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  • 新規な殺蚊Cry46Abトキシンの殺虫活性メカニズム

    早川徹, 榊原暁, 武部聡, 井出徹

    第63回日本応用動物昆虫学会大会  2019 

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    Event date: 2019.3.25 - 2019.3.27

    Language:Japanese   Presentation type:Oral presentation (general)  

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Awards

  • 生物学研究奨励賞

    2024.10   公益財団法人両備備檉園記念財団   殺蚊Btトキシンの殺虫活性コントロールを志向した基盤技術の開発

    早川徹

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Research Projects

  • 殺蚊Btトキシンの殺虫活性コントロールを志向した基盤技術の開発

    2024.10 - 2025.09

    (公財)両備檉園記念財団  2024年度 第46回 研究助成金 

    早川徹

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  • 膜蛋白を標的とする創薬支援装置の開発-産業応用に向けて- 分担課題:ヒトや環境に安全な微生物蚊防除剤開発への応用

    2024.06 - 2025.03

    令和6年度特別電源所在県科学技術振興事業における大学等委託研究 

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  • 殺蚊Btトキシンの小孔形成と殺⾍活性−殺⾍活性コントロール技術の開発に向けて−

    2022.04 - 2025.03

    日本学術振興会  科学研究費助成事業  基盤研究(C)

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Class subject in charge

  • Advanced Internship for Interdisciplinary Medical Sciences and Engineering (2024academic year) Year-round  - その他

  • Technical English for Interdisciplinary Medical Sciences and Engineering (2024academic year) Late  - その他

  • Research Works for Interdisciplinary Medical Sciences and Engineering (2024academic year) Year-round  - その他

  • Research Works for Interdisciplinary Medical Sciences and Engineering (2024academic year) Year-round  - その他

  • Mathematical and Data Sciences(Advanced) (2024academic year) Fourth semester  - 火1~2

  • Biotechnology experiment 2 (2024academic year) 1st semester  - 月5~8,木5~8

  • Biotechnology experiment 3 (2024academic year) Third semester  - 火5~8,金5~8

  • Biotechnology Experiment 1 (2024academic year) 1st semester  - 月5~8,木5~8

  • Biotechnology Experiment 2 (2024academic year) Third semester  - 火5~8,金5~8

  • Probability and Statistics 2 (2024academic year) Fourth semester  - 火1~2

  • Molecular Genetics and Biological Function (2024academic year) Prophase  - 火7~8

  • Advanced Internship for Interdisciplinary Medical Sciences and Engineering (2023academic year) Year-round  - その他

  • Technical English for Interdisciplinary Medical Sciences and Engineering (2023academic year) Late  - その他

  • Research Works for Interdisciplinary Medical Sciences and Engineering (2023academic year) Year-round  - その他

  • Research Works for Interdisciplinary Medical Sciences and Engineering (2023academic year) Year-round  - その他

  • Mathematical and Data Sciences(Advanced) (2023academic year) Fourth semester  - 火1~2

  • Biotechnology experiment 2 (2023academic year) 1st semester  - 月5~8,木5~8

  • Biotechnology experiment 3 (2023academic year) Third semester  - 火5~8,金5~8

  • Biotechnology Experiment 1 (2023academic year) 1st semester  - 月5~8,木5~8

  • Biotechnology Experiment 2 (2023academic year) Third semester  - 火5~8,金5~8

  • Probability and Statistics 2 (2023academic year) Fourth semester  - 火1~2

  • Technical English for Interdisciplinary Medical Sciences and Engineering (2022academic year) Late  - その他

  • Research Works for Interdisciplinary Medical Sciences and Engineering (2022academic year) Year-round  - その他

  • Mathematical and Data Sciences(Advanced) (2022academic year) Fourth semester  - 火1~2

  • Biotechnology experiment 2 (2022academic year) 1st semester  - 月5~8,木5~8

  • Biotechnology experiment 2 (2022academic year) 1st semester  - 月5~8,木5~8

  • Molecular Genetics and Biological Function (2022academic year) Prophase  - 火5~6

  • Technical English for Interdisciplinary Medical Sciences and Engineering (2021academic year) Late  - その他

  • Research Works for Interdisciplinary Medical Sciences and Engineering (2021academic year) Year-round  - その他

  • Mathematical and Data Sciences(Advanced) (2021academic year) Fourth semester  - 火1,火2

  • Biotechnology experiment 2 (2021academic year) 1st semester  - 月5,月6,月7,月8,木5,木6,木7,木8

  • Biotechnology experiment 2 (2021academic year) 1st semester  - 月5,月6,月7,月8,木5,木6,木7,木8

  • Technical English for Interdisciplinary Medical Sciences and Engineering (2020academic year) Late  - その他

  • Research Works for Interdisciplinary Medical Sciences and Engineering (2020academic year) Year-round  - その他

  • Biotechnology experiment 2 (2020academic year) 1st semester  - 月4,月5,月6,月7,木4,木5,木6,木7

  • Biotechnology experiment 2 (2020academic year) 1st semester  - 月4,月5,月6,月7,木4,木5,木6,木7

  • Molecular Genetics and Biological Function (2020academic year) Prophase  - 月1,月2

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