Mechanism Behind Animal Fluorescence may be Useful in Biotechnology

Scientists are a step closer to understanding the mechanism behind the mysterious fluorescent light naturally produced by certain animals, a skill that may be useful in the field of biotechnology, according to a new study.

In the study published in Scientific Reports, researchers from the University of California, San Diego describe lancelets, marine invertebrates also known as "amphioxus" that are capable of producing a natural fluorescent glow. The fish-shaped animal possesses green fluorescent proteins (GFPs) that allow them to emit both very bright and much dimmer versions of the light - a rare capability in the animal kingdom.

Fluorescence is the process of blue "excitation" light into green "emission" light, and though the exact mechanism that controls this ability remains unknown, this study, researchers say, opens the door towards its understanding.

Lead author Dimitri Deheyn and his colleagues looked into the structural differences of the GFPs, and found that some variations exist at the nanoscale level that allows the sea creature to emit different brightness levels. These differences lie in the stiffness around the animal's "chromophore pocket," the area of proteins responsible for molecular transformation of light, and thus the different light intensities.

"We discovered that some of the amphioxus GFPs are able to transform blue light into green light with 100 percent efficiency, which combines with other properties of light absorbance to make the amphioxus GFPs about five times brighter than current commercially available GFPs, resulting in effect to a huge difference," Deheyn said in a statement. "It is also interesting that the same animal will also express similar GFPs with an efficiency of about 1,000 times less."

Current engineered GFPs only reach 60 to 80 percent efficiency, so these lancelets offer the possibility of more efficient biotechnologies.

"The US Air Force, and the Department of Defense in general, uses a large variety of biosensors in biomedicine, bioengineering, and materials science, and providing proteins with the ability to be very bright can help technology advance because of better signal-to-noise ratio," Deheyn added.