Current Affiliation Organization 【 display / non-display 】

Current Affiliation Organization 【 display / non-display 】

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External Career 【 display / non-display 】

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Research Interests 【 display / non-display 】

Research Interests 【 display / non-display 】

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Research Areas 【 display / non-display 】

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Published Papers 【 display / non-display 】

• Asymmetrical physiological cost of reproduction shapes caste-specific resource allocation in an ant, <i>Diacamma</i> cf. <i>indicum</i> from Japan

  Yasunari Tanaka, Yusuke Ishizuka, Yu Matsuura, Jilin Pan, Hiroyuki Shimoji

  Royal Society Open Science ( The Royal Society )  13 ( 2 )   2026.02 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

  　View Summary

  Abstract In eusocial insects, queens demonstrate high reproductive capacity and extended longevity, representing examples of the trade-off in resource allocation. Workers perform non-reproductive tasks, such as caring for broods and foraging, thus reducing the energetic demands of queens. As queens dedicate their lives to reproduction, these reduced energetic demands enable them to live longer, laying many eggs. However, the physiological specialization of queens is markedly distinct from that of workers. This study examines the trade-off between immunocompetence and reproduction among castes in an ant species, Diacamma cf. indicum, from Japan, which lacks a morphological queen caste. First, gamergates (functional queens) exhibited higher expression of innate immunity genes than the workers. Second, to experimentally skew resource allocation towards immunocompetence, gamergates and reproductive workers were subjected to an immune challenge. As a result, the expression of the antimicrobial peptide gene Hymenoptaecin was increased in gamergates without compromising reproduction-related genes, such as Vitellogenin. By contrast, the expression of genes associated with reproduction was decreased in reproductive workers. Moreover, we revealed that gamergates possessed a remarkably low fat content, similar to non-reproductive foragers. These findings suggest that, while gamergates can overcome the trade-off, reproductive workers are constrained by the physiological costs of reproduction.

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• Asymmetrical physiological cost of reproduction shapes caste-specific resource allocation in an ant, Diacamma cf. indicum from Japan Japan

  Yasunari Tanaka, Yusuke Ishizuka, Yu Matsuura, Jilin Pan and Hiroyuki Shimoji

  Royal Society Open Science     2026 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

• A potential risk and management of feces in the queenless ant

  Y. Ishizuka, R. Yamashita, H. Itoh, Y. Matsuura, Y. Kikuchi, H. Shimoji

  Insectes Sociaux ( Springer Science and Business Media LLC )    2024.06 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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• Reproductive potentials of task-shifting workers in a queenless ant

  Yasunari Tanaka, Kohei Oguchi, Satoshi Miyazaki, Kiyoto Maekawa, Hiroyuki Shimoji

  Insectes Sociaux ( Springer Science and Business Media LLC )    2024.02 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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• Protocol to obtain long movement trajectories of leaders and followers in ant tandem runs

  Yasunari Tanaka, Gabriele Valentini, Stephen C. Pratt, Hiroyuki Shimoji, Nobuaki Mizumoto

  STAR Protocols ( Elsevier BV )  4 ( 4 ) 102769 - 102769   2023.12 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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Grant-in-Aid for Scientific Research 【 display / non-display 】

Grant-in-Aid for Scientific Research 【 display / non-display 】

• Challenging research (sprout)

  Project Year: 2023.06  -  2026.03 

  Direct: 5,000,000 (YEN)  Overheads: 6,500,000 (YEN)  Total: 1,500,000 (YEN)

• Molecular bases and evolutionary process of the in vivo flagellar drill motility.

  Grant-in-Aid for Transformative Research Areas (B)

  Project Year: 2022.05  -  2025.03 

  Direct: 41,200,000 (YEN)  Overheads: 53,560,000 (YEN)  Total: 12,360,000 (YEN)

• Grant-in-Aid for Scientific Research(B)

  Project Year: 2022.04  -  2025.03 

  Direct: 13,300,000 (YEN)  Overheads: 17,290,000 (YEN)  Total: 3,990,000 (YEN)

• Invasion mechanisms of exotic ants with special focus on Japanese invaders

  Grant-in-Aid for Scientific Research(A)

  Project Year: 2015.04  -  2020.03 

  Direct: 32,300,000 (YEN)  Overheads: 41,990,000 (YEN)  Total: 9,690,000 (YEN)

• A new synthesis through the concept of interaction between different levels of the biological hierarchy

  Grant-in-Aid for Scientific Research(B)

  Project Year: 2015.04  -  2018.03 

  Investigator(s): TSUJI Mizuki 

  Direct: 13,900,000 (YEN)  Overheads: 18,070,000 (YEN)  Total: 4,170,000 (YEN)

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  We addressed questions on interaction between different levels of the biological hierarchy in order to integrate micro and macro ecologies. We especially focused on the relationship between intra-specific dynamics, such as kin selection and sexual selection, and inter-specific dynamics, such as host-parasite dynamics and model-mimic dynamics, in the community through theoretical and empirical approaches. We empirically showed examples (though some are yet potential) of such adaptive dynamics in ants, clonal plants, butterflies, fish and other systems.

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Social Activity 【 display / non-display 】

Social Activity 【 display / non-display 】

• 2024.04

  　

  　

  

• 2025.11

  　

  　

  

• 2023.07