The luciferase gene -- the DNA segment that gives rise to the firefly's light-producing chemistry -- has been isolated. It has been transferred into the cells of tobacco plants and monkeys, making plants and animals glow with an eerie green light.
Researchers have also isolated light-producing genes from a Jamaican beetle called the kittyboo. Kittyboo genes give expression to four colors of light, and these have been introduced into yet other organisms. Scientists have learned how to make plants and animals glow with a rainbow of hues.
There is purportedly a serious purpose behind this research. The luciferase gene is a tag or marker that can be detected by the luminescence it stimulates. For example, chemicals from a firefly's tail can be added to the urine sample of a patient who may be suffering from bacterial infection; if bacteria are present in the urine, the firefly extract will make them glow with a faint but detectable light. The lights of the firefly and kittyboo are also used to study gene expression, monitor plant diseases, track the spread of toxins in the environment, detect cancerous tissue, even monitor brain activity in living animals.
One can imagine other uses.
Light is the ultimate aphrodisiac.
Where geneticists lead, the commerce of sex might follow. Think of it (he said, tongue in cheek). Human lovers glowing in the dark with the glowworm's light, like a luminous perfume. Imagine the ads in GQ and Vogue for bioluminescence genes by Mennen and Clinique. "Let Estee Lauder make you glow with love's soft light."
Once the luciferase gene is in the body, the light will be turned on and off according to the demands of romance, perhaps by catalyzing the reaction with the hormonal secretions of sex. Lovers will ignite with the kittyboo glow of desire. Their eyes will shine with the firefly's come-hither light.
The old song had it right. The glowworm will lead us on to love.