Otaki Joji

写真a

Title

Professor

Researcher Number(JSPS Kakenhi)

70360211
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Current Affiliation Organization 【 display / non-display 】

  • Duty   University of the Ryukyus   Faculty of Science   Chemistry, Biology and Marine Science   Professor  

  • Concurrently   University of the Ryukyus   Graduate School of Engineering and Science   Marine and Environmental Sciences   Professor  

  • Concurrently   University of the Ryukyus   Graduate School of Engineering and Science   Chemistry, Biology and Marine Science   Professor  

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University 【 display / non-display 】

  • 　
    -
    1992.03

    University of Tsukuba     Graduated

  • 　
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    1994.02

    University of Massachusetts at Amherst   Faculty of Science   Graduated

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Graduate School 【 display / non-display 】

  • 　
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    1997.10

    Columbia University    Doctor's Course (first term)  Completed

  • 　
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    1998.05

    Columbia University    Doctor's Course (first term)  Completed

  • 　
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    2000.05

    Columbia University  Graduate School, Division of Bioresearch  Doctor's Course  Completed

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Academic degree 【 display / non-display 】

  • Columbia University -  Ph.D.

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External Career 【 display / non-display 】

  • 2000.03
    -
    2001.05

    Postdoctoral fellow, University of Cambridge, Department of Medicine  

  • 2002.04
    -
    2006.02

    Kanagawa University, Assistant Professor  

  • 2006.03
    　
    　

    University of the Ryukyus, Faculty of Science, Department of Chemistry, Biology, and Marine Science, Cell and Functional Biology, Associate Professor  

  • 2006.03
    -
    2021.03

    University of the Ryukyus, Faculty of Science, Department of Chemistry, Biology, and Marine Science, Cell and Functional Biology, Associate Professor  

  • 2021.04
    　
    　

     

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Research Areas 【 display / non-display 】

  • Life Science / Developmental biology

  • Life Science / Molecular biology

  • Life Science / Animal physiological chemistry, physiology and behavioral biology

  • Life Science / Morphology and anatomical structure

  • Developmental Biology

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Research Theme 【 display / non-display 】

  • Color Pattern Formation in Butterfly Wings

  • Sequence decoding based on short constituent sequences in proteins

  • Study on Olfactory Sensory Neurons

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Published Papers 【 display / non-display 】

  • Dynamic Physical Distortions of Butterfly Pupal Wings: Potential Mechanical Signals from Eyespot Organizers for Color Pattern Determination

    Nakazato Yugo, Hirose Euichi, Otaki Joji M.

    Biology ( MDPI )  15 ( 11 ) 1 - 32   2026.05 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

    　View Summary

    Butterfly wing color patterns are determined in pupal wing tissues, in which the prospective eyespot focus functions as a developmental organizer. Here, we investigated the microscopic structures of pupal wing tissues containing an eyespot organizer in line with the physical distortion hypothesis. Histochemical staining revealed that the pupal cuticle and epidermis were wavy and thin at 6 h but smooth and thick at 12 h postpupation. The eyespot organizer was associated with the thickest cuticle layer, called the cuticle focal spot. Transmission election microscopy (TEM) revealed that the intervening space (IVS) between the cuticle layer and the cellular apical end was wide at 6 h but narrow at 12 h postpupation. The spatial relationship between cuticle thickness and IVS width was indicative of mechanical buckling of the region adjacent to the cuticle focal spot. Live in vivo imaging revealed that the IVS at and near the eyespot organizer trapped orange fluorescent protein (OFP) injected into hemolymph. Dynamic distortions of the pupal wing epidermis and cuticular surface were detected in live individuals over time. These results suggest that physical distortions of the wing tissue induced by differential cuticle synthesis and subsequent buckling may function as mechanical morphogenic signals from eyespot organizers.

  • Pharmacological Effects of NADPH Oxidase Inhibitors on Butterfly Wing Morphogenesis and Color Pattern Formation in <i>Junonia orithya</i>

    Nakazato, Y; Ozaki, M; Suenaga, R; Otaki, JM

    INSECTS ( Insects )  17 ( 3 )   2026.03 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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  • TRPA1 for Butterfly Eyespot Formation

    Ozaki, M; Otaki, JM

    INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES ( International Journal of Molecular Sciences )  27 ( 3 )   2026.01 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

  • Pharmacological Intervention of PIEZO1 for Butterfly Eyespot Color Patterns in Junonia orithya

    Ozaki Momo, Otaki Joji M.

    Receptors ( MDPI )  4 ( 4 ) 1 - 28   2025.10 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

    　View Summary

    Background: PIEZO channels are mechanoreceptors expressed in various cells. Their contributions to animal development are not entirely clear. According to the physical distortion hypothesis, developmental organizers for butterfly wing eyespots receive and release mechanical signals in pupal wing tissues during development, initiating a calcium signaling cascade and gene expression changes. Objectives: We tested the possible involvement of PIEZO1 in butterfly wing color pattern formation, according to the physical distortion hypothesis. Methods: We performed a pharmacological intervention of PIEZO1, focusing on the eyespots of Junonia orithya. Chemical modulators of PIEZO1 and the actin cytoskeleton were injected into pupae immediately after pupation during the critical period of color pattern determination, and the eyespot color patterns of the emerging adult wings were analyzed. We also tested dimethyl sulfoxide (DMSO) because it was used as a solvent. Results: DMSO significantly enlarged most eyespots examined. In contrast, the specific PIEZO1 activator Jedi2 induced significant reduction in the dorsal hindwing eyespots. Another specific PIEZO1 activator, Yoda1, also induced similar changes, although less clearly. The mechanosensitive channel blocker GsMTx4 produced compromised eyespots in an individual, although statistical support for modification was weak. The actin polymerization activator phalloidin induced blue foci in the ventral forewing eyespots. PIEZO expression in the pupal wings was demonstrated by RT-PCR. Conclusions: These results suggest that eyespot organizers in butterfly wings may employ a PIEZO-mediated mechanotransduction pathway to regulate eyespot color patterns, supporting the physical distortion hypothesis. These results highlight the importance of PIEZO in developmental organizers in animals.

  • Spatiotemporal Dynamics of Genetic Diversity in the Pale Grass Blue Butterfly After the Fukushima Nuclear Accident

    Toki, M; Taira, W; Sakauchi, K; Otaki, JM

    DIVERSITY-BASEL ( Diversity )  17 ( 10 )   2025.09 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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Academic Awards 【 display / non-display 】

  • Fujii Award

    2011.09.23   Zoological Society  

  • Zoological Science Award

    2011.09.23   Zoological Society  

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