The latest study from Osaka Metropolitan University uncovers a dragonfly opsin that detects deep-red light up to about 720 nm. This discovery sheds new light on insect vision and hints at some promising uses in deep-tissue optogenetics.
Researchers analyzed absorption spectra across several dragonfly opsins. They found one with a peak around 580 nm that still responds past 700 nm.
Dragonflies seem to use a mechanism similar to mammals for long-wavelength sensitivity, though the trait evolved independently. It’s a striking example of convergent evolution—nature’s way of finding similar solutions in very different creatures.
The team’s spectral survey measured absorption across multiple dragonfly opsins. They pinpointed a candidate with a 580 nm peak that stretches sensitivity into the red.
This long-wavelength reach comes from a molecular trick that, while echoing mammalian vision, developed on its own in dragonflies. It’s honestly fascinating how different lineages end up with such similar adaptations.
To test if this matters for dragonflies, researchers looked at reflections from yellow body stripes in both males and females. They noticed small color differences above 530 nm, which red-sensitive vision could amplify during those frantic courtship flights.
That means dragonflies might use this nuanced color discrimination at red wavelengths to spot subtle mate signals. In a fast-paced aerial environment, every little visual edge counts.
The link between spectral tuning and behavior suggests red sensitivity could give dragonflies an advantage in rapid visual scenes. It might help them pick out rivals or mates with more precision than if they only saw in blue-green.
In another part of the study, the team swapped in a single amino acid from a mantis shrimp opsin to make a red-shifted variant. This engineered opsin pushes the absorption peak about 10 nm further into the red.
When they expressed this version in cells, it triggered a tenfold stronger response to 738 nm near-infrared light compared to the native dragonfly opsin.
- Red-shifted activation lets researchers control cells using even deeper near-infrared light.
- Stronger cellular responses mean more efficient optical stimulation at the same wavelength.
The improved near-infrared sensitivity suggests this dragonfly-derived opsin could activate cells deeper in living tissue than current optogenetic tools. It could open up non-invasive or less-invasive ways to modulate nerves and muscles in research, maybe even therapy someday.
Convergent evolution and future directions
The findings show a rare case of convergent evolution in spectral tuning between insects and vertebrates. They also hint at new ways to design better deep-tissue optogenetic actuators, especially by looking at dragonfly opsins.
If researchers mix evolutionary insight with engineering, they might tweak wavelength sensitivity for specific experiments or clinical needs. That could expand the toolkit for controlling biological systems with light.
Honestly, it’s a reminder of how much we can learn from unusual visual systems when it comes to bioengineering. Dragonfly opsins aren’t just interesting for figuring out how fast-moving insects see—there’s real potential here for building optogenetic strategies that dig deeper into living tissue.
Here is the source article for this story: Dragonfly Vision Offers Clues for Deep-Tissue Optogenetics