Bioluminescence is used in scientific research every day. It helps scientists study the genetic code and look for ways to repair genetic damage. It helps in the search for new ways to fight disease, and in the study of the nervous system as well as other body systems essential to human life.
Scientists sometimes attach reporter genes to the snippets of DNA that they are attempting to add to a DNA sequence. Attaching a marker gene with an effect that can easily be seen and evaluated lets researchers know that the molecule they are working on has actually been modified.
For example, the gene that encodes jellyfish green florescent protein might be included in a sequence. If a new bit of DNA containing the protein has been successfully attached to a sequence, the new molecule will glow green in blue light. Sometimes the light-promoting enzyme luciferase is used instead, or another component of a bioluminescent organism’s genetic code. Any of these molecules can let researchers see when they are making progress by simply observing the culture that contains modified DNA.
Quorum sensing is the scientific term for the way certain bacteria take a census of their local population. A number of bacteria species change their behaviors, and even their nature, when they are gathered in large groups. Some might become light producing, and others might become toxin producing. The mechanisms that underlie these changes might someday be subverted to control microbe populations without antibiotics.
Some marine bacteria, for example, release a signaling molecule into their environment. Each bacterium senses the concentration of the molecule in the area, and from that concentration, gains awareness of how many of their species are nearby.
The Vibrio fischeri organism is free living in the open ocean, but also colonizes the photophore organs of certain marine animals. In a photophore, this vibrio causes bioluminescence, helping the squid camouflage itself. In the open ocean, bioluminescence would be purposeless for the microbe, and a severe energy drain.
Quorum sensing helps the vibrio conserve energy, so it survives to live in symbiosis with the squid.
However, some types of bacteria that signal in a similar way are known to be pathogens, such as Yersinia pestis, plague. How useful it would be to fool pathogenic bacteria into acting as if they were alone, and would be wasting energy by producing toxins. This particular form of quorum sensing was first explored in V. fischeri, when scientists explored its bioluminescence in the Hawaiian bobtail squid.
Aequorin is isolated from bioluminescent sea life. Osama Shimumora was the first scientist to isolate the molecule. It is used in molecular biology to track neural and other activity, because when a nerve impulse travels it leaves a trail of calcium ions. The luminous protein reacts to the ions and makes this trail visible as light. Other useful compounds include cameleon, and TN-XXL, which also signal with light.
It almost seems like science fiction, but bioluminescence is used in scientific research every day, by scientists seeking to prevent disease rather than merely treat it. Someday, perhaps, disease-causing bacteria’s defenses will be turned against them. Then science can redirect the resources it now expends fighting disease towards helping each person realize his or her full genetic potential.