The Groundbreaking Discovery at Osaka Metropolitan University
Researchers at Osaka Metropolitan University (OMU) have uncovered a remarkable similarity in how dragonflies and humans perceive red light, revealing a case of parallel evolution in visual systems. This finding, detailed in a study published in Cellular and Molecular Life Sciences, shows that dragonflies use a red-sensitive opsin protein—known as RhLWA2—with a light absorption maximum at 580 nanometers (nm), extending into near-infrared ranges. Opsins are G-protein coupled receptors (GPCRs) in the eye that bind to retinal, a vitamin A derivative, to form light-sensitive pigments essential for vision.
The study, led by graduate student Ryu Sato and Professors Mitsumasa Koyanagi and Akihisa Terakita from OMU's Graduate School of Science, challenges previous assumptions about insect vision. While mammals like humans tune their red opsins through specific amino acid substitutions at position 292 in the protein sequence, dragonflies employ the same mechanism independently. This convergence highlights how evolutionary pressures can lead to identical solutions in distantly related species.
Dragonflies, renowned for their compound eyes containing up to 30,000 ommatidia (individual visual units), possess an extraordinary array of opsins, far surpassing the three cone opsins in human eyes. Yet, this research pinpoints RhLWA2 as their primary red opsin, bistable in nature—meaning it can revert between active and inactive states upon different light exposures—making it uniquely suited for dynamic environments like aerial hunting and mating.
At OMU, this work exemplifies the university's strength in photobiology and sensory neuroscience, fields where Japan excels globally. Formed in 2022 from the merger of Osaka City University and Osaka Prefecture University, OMU now hosts over 16,000 students and emphasizes interdisciplinary research in life sciences.
Unraveling the Molecular Mechanism
The team's methodology combined heterologous action spectroscopy (HAS)—expressing dragonfly opsins in human embryonic kidney (HEK293) cells—to screen for sensitivity, with UV-Vis spectroscopy for precise absorption maxima. They confirmed RhLWA2's λ_max at 580 nm and its bistability via high-performance liquid chromatography (HPLC), which tracked retinal isomerization from 11-cis to all-trans upon red light exposure.
Site-directed mutagenesis revealed position 292 as the spectral tuning hotspot. In shorter-wavelength dragonfly opsins, serine (S292) or alanine (A292) predominates; valine (V292) in RhLWA2 red-shifts sensitivity, mirroring human chloropsin. Further, a V211C mutation engineered a variant with λ_max at 590 nm, eliciting calcium responses in cells to 738 nm near-infrared light—10-fold stronger than wild-type at certain intensities.
- Key Mutations: V292S shifts λ_max to 546 nm; V292A to 562 nm; wild-type V292 enables 580 nm.
- Bistability: Red light (>640 nm) decays pigment to ~550 nm state; green reverses it.
- Optogenetic Potential: NIR-responsive cells for deeper tissue control.
This precision engineering underscores OMU's advanced facilities, including protein expression labs and spectroscopy suites, vital for Japan's competitive biotech landscape.
Profiles of the Research Team
Professor Mitsumasa Koyanagi, corresponding author, specializes in photobiology, with prior work on non-visual opsins like parapinopsins. His lab at OMU explores GPCR signaling in light detection. Co-author Professor Akihisa Terakita, a pioneer in discovering jellyfish opsin-Gs cascades, directs efforts in opsin diversity. Graduate student Ryu Sato executed experiments, highlighting OMU's mentorship model for young researchers.
Funding from MEXT KAKENHI grants (e.g., JP22H02663 to Koyanagi), JST PRESTO/CREST, and JSPS Fellows supported this, reflecting Japan's ~¥1 trillion annual science budget, with biology securing significant shares.
OMU's Graduate School of Science enrolls ~500 master's and PhD students in biology, emphasizing hands-on research. This project involved collaboration with OMU's Advanced Research Institute for Natural Science and Technology, fostering translational biology.
Evolutionary Parallels and Ecological Advantages
Parallel evolution at position 292 suggests common selective pressures for red vision: mate recognition in dragonflies via thorax reflectance differences (males higher in 580-720 nm), predator avoidance, or foraging. In Gomphidae dragonflies, yellow wax layers reflect red/NIR distinctly by sex, optimized for RhLWA2 sensitivity.
Japan's biodiversity hotspots like wetlands host diverse Odonata, aiding field studies. Ryo Futahashi's prior work at National Institute of Genetics documented dragonfly opsin diversity (>20 types), setting the stage for OMU's tuning analysis.
Comparative genomics across Japanese universities, like Kyoto U's insect vision labs, reveals arthropod-mammal convergence, enriching evolutionary biology curricula.
Photo by Alexey Demidov on Unsplash
Applications in Optogenetics and Medical Devices
The NIR-tuned opsin promises optogenetic tools for deep-brain stimulation, retinal prosthetics, and cancer therapy, where NIR penetrates tissues better than visible light. Japan's optogenetics scene thrives at UTokyo (Johansen Lab), Kyoto U, and Nagoya Tech's OptoBioTechnology Center.
Read the full paper here for technical details. OMU's findings align with Japan's biotech push, with ¥800 billion R&D funding in 2026.
Potential for retinal implants mimicking dragonfly sensitivity could aid Japan's aging population (29% over 65 by 2026).
OMU's Strengths in Biological Sciences
OMU's Biology Department explores life's essentials and biodiversity, from microbes to animals. With ~200 undergrads and 100 grads annually, it boasts labs for spectroscopy, electrophysiology, and transgenics. Recent feats include RNA neuroscience and ecology.
Japan's top biology unis (UTokyo #1, Kyoto #2 per EduRank 2026) enroll ~50,000 biology students; OMU ranks high in citations.
Vision Research Landscape in Japanese Universities
Japan leads opsin research; Terakita/Koyanagi pioneered non-visual opsins. Labs at UTokyo (Murakami Vision Lab), Kyoto U (computer vision), RIKEN (neuroscience) complement OMU. MEXT funds ~¥200 billion for life sciences, supporting 10,000+ grad researchers.
Biotech hubs like Kobe's iPS Cell Institute link vision to regenerative medicine.
Career Opportunities in Japan's Biotech Sector
This discovery boosts demand for neuroscientists, with OMU grads entering firms like Takeda or startups in optogenetics. Japan aims 10x AI supercomputers by 2030, aiding protein modeling.
- Faculty roles in biology depts (e.g., lecturer salaries ~¥8-12M/year).
- Postdocs via JSPS (¥4M/year).
- Industry: Biotech VC up 20% in 2026.
Future Outlook and Global Impact
OMU plans NIR opsin variants for clinical trials. Amid Japan's 92% grad employment, this positions biology as key for Viksit Japan-like innovation. International collaborations grow, with 229K intl students.
OMU press release details more. This elevates Japanese higher ed in sensory biology.