Sometimes, different animals end up using the same trick to solve a problem. Scientists call this parallel evolution. A team at Osaka Metropolitan University discovered that dragonflies sense red light in almost the same way humans do.
Human eyes have tiny proteins called opsins. Three kinds of opsins let us see blue, green and red colors. Dragonflies have a special opsin that reacts to light around 720 nm – a shade deeper than the reddest color most people can see.
"It is one of the most red‑sensitive pigments we have ever found," said Professor Akihisa Terakita. "Dragonflies can probably see farther into the red spectrum than other insects."
Why Red Vision Helps Dragonflies
The researchers think this ability helps dragonflies find mates. They measured how much light the insects reflect. Male and female dragonflies showed clear differences in the amount of red‑to‑near‑infrared light they bounced back.
These subtle color cues may let a male spot a female quickly while both are flying.
A Surprising Parallel with Mammals
Even though insects and mammals are far apart on the family tree, both have arrived at a similar molecular method for detecting red light.
Engineering the Opsin for Medicine
The team also found a single spot in the opsin protein that decides which wavelength it reacts to. By changing this spot, they pushed the protein’s sensitivity toward even longer, near‑infrared light.
Cells that carried the modified protein lit up when exposed to near‑infrared light, showing the protein works in a new range.
Potential Use in Optogenetics
This breakthrough could be useful for optogenetics – a technique that uses light‑sensitive proteins to control cells inside living tissue. Longer wavelengths travel deeper into the body, so a near‑infrared‑responsive opsin could reach cells that are hard to access with visible light.
Professor Mitsumasa Koyanagi said the altered dragonfly opsin "can trigger cellular responses with near‑infrared light," making it a promising tool for research and therapy.
The findings were published in Cellular and Molecular Life Sciences.