Bioluminescence Research
Posted April 1, 1998
Have you ever watched fireflies flash their greetings on a summer night? If you have, then you already are familiar with bioluminescence. Bioluminescence is the emission
of light from an organism. In nature, many organisms are bioluminescent. Fireflies, jellyfishes, squid, bacteria, dinoflagellates, deep sea fishes, and even fungi produce light. Recently
genetic researchers have isolated the gene that codes for the enzyme luciferase, which is responsible for producing bioluminescence in fireflies. They spliced this gene into the DNA
of salmonella bacteria (bacteria that cause food poisoning). When mice were infected with glowing bacteria, scientists were able to trace the immune response of the mice to these bacteria.
The mice glowed as the bacterial infection spread throughout their tissues. Later, scientists treated the mice with antibiotics that kill salmonella bacteria. They knew when the antibiotic
killed off the bacteria because they watched the flashes of light diminish until they were gone.
Other genetic engineers have removed the gene for a glowing molecule produced by a species of jellyfish and inserted it into embryos of zebrafish. The gene was engineered
to turn on only in red blood cells. The red blood cells with this gene would glow green when exposed to blue light. Why would a biologist want to produce glowing fishes? Biologists are
interested in the development of red blood cells in a variety of organisms. By following the glowing red blood cells in zebrafish embryos, scientists discovered that red blood cells
are produced in the heart during early development. Later on in zebrafish development, the production of red blood cells moves to the kidneys. Studying the early stages of red blood
cell production may enable scientists to identify the gene responsible for their production. Researchers also are studying glowing nerve cells in these fish to determine how nerve cells
form connections within a developing brain.
With bioluminescence, scientists may be able to follow gene expression, trace development, and even screen for the potential of new drugs. For example, cultured human
cells can be made to glow when invaded by HIV. If the glowing stops when a certain drug is added, that could mean that HIV replication has stopped. Thus, that drug might show promise
as a treatment for HIV-infected patients.
References
Taubes, Gary. "Firefly Gene Lights Up Lab Animals From Inside Out." Science, 276, June 27, 1997, p. 1993.
Travis, J. "It Came from Earth: Green-blooded fish," Science News, 152, October 18, 1997, p. 247.
Woods, Heather Rock. "Lights, Camera, Biology in Action," Stanford Medicine, 15(1), Fall 1997, pp. 8-13, 32.
Contag, Christopher H., Stanley D. Spilman, Pamela R. Contag, Masafumi Oshiro, Brian Eames, Phyllis Dennery, David K. Stevenson, David A. Benaron. "Visualizing Gene
Expression in Living Mammals Using a Bioluminescent Reporter," Photochemistry and Photobiology, 66(4), October 1997, pp. 523-531.
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