The Price of 'Immobile' Evolution? Similarities Between Beetles Playing Dead and Parkinson's Disease - Okayama University, Tokyo University of Information Sciences, Tokyo University of Agriculture, Tamagawa University
A joint research team including Okayama University discovered that the physiological and genetic characteristics of beetles that maintain 'tonic immobility' (playing dead) for extended periods share commonalities with human Parkinson's disease. Decreased brain dopamine levels, abnormal motor activity, and mutations in related genes were confirmed, indicating potential for developing new therapeutic strategies for Parkinson's disease.
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- 📰 Published: April 30, 2026 at 06:10
- 🔍 Collected: April 29, 2026 at 21:31
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Okayama University, Tokyo University of Information Sciences, Tokyo University of Agriculture, and Tamagawa University have jointly announced research findings.
April 29, 2026 (Reiwa 8)
National University Corporation Okayama University
https://www.okayama-u.ac.jp/
Key Points:
Parkinson's disease is a progressive neurodegenerative disorder causing motor dysfunction due to impaired function of dopaminergic neurons in the brain, and a fundamental cure has yet to be established.
In this study, artificial strains of beetles that maintain 'tonic immobility' (playing dead) for a long time were created, and their physiological and genetic characteristics were analyzed. In strains with prolonged tonic immobility, a decrease in brain dopamine levels, abnormal motor activity, and changes in the expression of genes involved in dopamine synthesis and tyrosine metabolism were confirmed. These characteristics were found to be common with those observed in human Parkinson's disease.
Furthermore, DNA sequence comparisons with genes involved in human dopaminergic pathways revealed numerous mutations in the long-duration tonic immobility strains, suggesting the existence of a molecular basis linking behavioral evolution and neurodegenerative diseases. These research findings indicate the possibility of understanding the pathogenesis of Parkinson's disease using simple insect models and establishing a foundation for new therapeutic strategies.
Overview:
Professor Takahisa Miyatake of the Graduate School of Environmental and Life Science at Okayama University, Associate Professor Keisuke Tanaka of Tokyo University of Information Sciences, Professor Ken Sasaki of Tamagawa University, and Professor Shunsuke Yajima of the Center for Genome Analysis at Tokyo University of Agriculture conducted DNA sequence comparisons between strains of the red flour beetle (Tribolium castaneum) that maintain prolonged 'tonic immobility' (playing dead) as a result of selective breeding, and genes involved in human Parkinson's disease-related dopaminergic pathways.
Previously, strains that maintain tonic immobility for a long time were known to have low dopamine expression in the brain, exhibited abnormal walking activity, and their motor ability could be restored by dopamine injection, indicating similarities to Parkinsonian syndrome.
Through this DNA sequence comparison with genes involved in human dopaminergic pathways, numerous mutations were found in the long-duration tonic immobility strains, suggesting the existence of a molecular basis linking behavioral evolution and neurodegenerative diseases.
These research findings were published online in 'Scientific Reports,' a Springer Nature publication, at 7:00 PM (Japan time) on March 17, 2026.
This matter was released on April 29, 2026.
Comment from Professor Takahisa Miyatake:
"Since 1997, I have continued to investigate the mystery of tonic immobility behavior. I realized that strains that play dead for a long time are usually not very active, and together with my collaborators, we discovered that this is due to dopamine deficiency in the brain. As our research progressed, the connection to Parkinsonian syndrome became apparent. Research on 'playing dead,' which seemed to have no practical use in human life, has developed into a relationship with human diseases. This demonstrates the importance of basic research."
Paper Information:
Title: Tribolium castaneum with longer duration of tonic immobility have more variations corresponding to the human Parkinson's disease genomic region
Japanese Title: "Red flour beetle strains with longer tonic immobility duration exhibited more variations corresponding to human Parkinson's disease-related genomic regions"
Journal: Scientific Reports
Authors: Keisuke Tanaka, Ken Sasaki, Shunsuke Yajima, Takahisa Miyatake
DOI: 10.1038/s41598-026-40050-3
Research Funding:
This research was supported by KAKENHI (Grant-in-Aid for Scientific Research) B "Genomic Behavioral Ecology: Genes Controlling 'Animal Movement' and Their Impact on Individual Fitness and Populations: Grant Number 23K21343" and KAKENHI C "Ecological Elucidation of Selective Pressures Causing Behavioral Variation in 'Movement/Immobility' in Organisms: Grant Number 25K09771," and support from the "Bioresource Genome Analysis Center" at Tokyo University of Agriculture.
For more detailed research content:
"The Price of 'Immobile' Evolution? Similarities Between Beetles Playing Dead and Parkinson's Disease"
https://www.okayama-u.ac.jp/up_load_files/press_r7/press20260317-1.pdf
Reference:
Okayama University, Graduate School of Environmental and Life Science, Insect Ecology Laboratory (Professor Takahisa Miyatake)
https://sites.google.com/view/miyatake/home
Keywords:
April 29, 2026 (Reiwa 8)
National University Corporation Okayama University
https://www.okayama-u.ac.jp/
Key Points:
Parkinson's disease is a progressive neurodegenerative disorder causing motor dysfunction due to impaired function of dopaminergic neurons in the brain, and a fundamental cure has yet to be established.
In this study, artificial strains of beetles that maintain 'tonic immobility' (playing dead) for a long time were created, and their physiological and genetic characteristics were analyzed. In strains with prolonged tonic immobility, a decrease in brain dopamine levels, abnormal motor activity, and changes in the expression of genes involved in dopamine synthesis and tyrosine metabolism were confirmed. These characteristics were found to be common with those observed in human Parkinson's disease.
Furthermore, DNA sequence comparisons with genes involved in human dopaminergic pathways revealed numerous mutations in the long-duration tonic immobility strains, suggesting the existence of a molecular basis linking behavioral evolution and neurodegenerative diseases. These research findings indicate the possibility of understanding the pathogenesis of Parkinson's disease using simple insect models and establishing a foundation for new therapeutic strategies.
Overview:
Professor Takahisa Miyatake of the Graduate School of Environmental and Life Science at Okayama University, Associate Professor Keisuke Tanaka of Tokyo University of Information Sciences, Professor Ken Sasaki of Tamagawa University, and Professor Shunsuke Yajima of the Center for Genome Analysis at Tokyo University of Agriculture conducted DNA sequence comparisons between strains of the red flour beetle (Tribolium castaneum) that maintain prolonged 'tonic immobility' (playing dead) as a result of selective breeding, and genes involved in human Parkinson's disease-related dopaminergic pathways.
Previously, strains that maintain tonic immobility for a long time were known to have low dopamine expression in the brain, exhibited abnormal walking activity, and their motor ability could be restored by dopamine injection, indicating similarities to Parkinsonian syndrome.
Through this DNA sequence comparison with genes involved in human dopaminergic pathways, numerous mutations were found in the long-duration tonic immobility strains, suggesting the existence of a molecular basis linking behavioral evolution and neurodegenerative diseases.
These research findings were published online in 'Scientific Reports,' a Springer Nature publication, at 7:00 PM (Japan time) on March 17, 2026.
This matter was released on April 29, 2026.
Comment from Professor Takahisa Miyatake:
"Since 1997, I have continued to investigate the mystery of tonic immobility behavior. I realized that strains that play dead for a long time are usually not very active, and together with my collaborators, we discovered that this is due to dopamine deficiency in the brain. As our research progressed, the connection to Parkinsonian syndrome became apparent. Research on 'playing dead,' which seemed to have no practical use in human life, has developed into a relationship with human diseases. This demonstrates the importance of basic research."
Paper Information:
Title: Tribolium castaneum with longer duration of tonic immobility have more variations corresponding to the human Parkinson's disease genomic region
Japanese Title: "Red flour beetle strains with longer tonic immobility duration exhibited more variations corresponding to human Parkinson's disease-related genomic regions"
Journal: Scientific Reports
Authors: Keisuke Tanaka, Ken Sasaki, Shunsuke Yajima, Takahisa Miyatake
DOI: 10.1038/s41598-026-40050-3
Research Funding:
This research was supported by KAKENHI (Grant-in-Aid for Scientific Research) B "Genomic Behavioral Ecology: Genes Controlling 'Animal Movement' and Their Impact on Individual Fitness and Populations: Grant Number 23K21343" and KAKENHI C "Ecological Elucidation of Selective Pressures Causing Behavioral Variation in 'Movement/Immobility' in Organisms: Grant Number 25K09771," and support from the "Bioresource Genome Analysis Center" at Tokyo University of Agriculture.
For more detailed research content:
"The Price of 'Immobile' Evolution? Similarities Between Beetles Playing Dead and Parkinson's Disease"
https://www.okayama-u.ac.jp/up_load_files/press_r7/press20260317-1.pdf
Reference:
Okayama University, Graduate School of Environmental and Life Science, Insect Ecology Laboratory (Professor Takahisa Miyatake)
https://sites.google.com/view/miyatake/home
Keywords: