I am a microbiologist and molecular biologist turned tenured biotech faculty turned bioinformatics scientist turned entrepreneur. My passion is developing instructional materials for 21st century biology (
DigitalBio RSS feed
Reposted in honor of the "glow in the dark" kitty clones.
Last year, I wrote about photographs of jellyfish that were altered by newspapers, scientific publishers, science education companies, and me (for the purpose of the article) to make it look like the jellyfish glowed.
Those jellyfish do NOT glow. Those images lie or at least misrepresent the truth.
But that doesn't mean that glowing animals don't exist. These pictures were taken under natural light and came from GloFish®.
Normally zebrafish are white with black stripes, but these zebrafish were genetically engineered to produce a fluorescent protein that makes the fish glow. The company web site doesn't identify the protein, but I would guess they use different mutant versions of green fluorescent protein (GFP).
Fish as pollution detectors
There's also an interesting story from the National University of Singapore about the development of these fish. The eventual goal is to use fish like these, as pollution detectors. The idea is that you could put detector fish into water, and if the water contained pollutants, the fish would glow. Environmental companies already do toxicity assays where they detect pollutants by putting fish into water. If the water contains harmful substances, the fish usually die or produce deformed offspring. Glowing fish could make the assay quicker. If toxic compounds can be detected more quickly, then rivers, streams, and lakes could be protected more quickly.
How would this work?
I'm cutting out a few steps, but this is the basic idea. Genes can be "turned on" or "turned off" when substances in the environment send the right kind of message to a cell. When the message is received, special kinds of proteins binds to specific sequences of DNA. These proteins attract other proteins, who make an RNA copy of the DNA. The RNA copy contains the directins for making the protein (GFP). GFP undergoes a chemical reaction and begins to glow.
The net result would be detector fish that would start to glow in the presence of harmful substances.
I don't know if the technology is worked out yet for the detector fish.
GloFish® on the other hand, are pets. They glow in clean water and live longer in clean water, too.
Reference:
1. GloFish® www.glofish.com
2. Zebrafish as pollution indicators, Natural University of Singapore, accessed Oct. 12, 2006.
technorati tags: biology, fish, green fluorescent protein, GFP, biotechnology, zebrafish,
Comments
A practical difficulty with glowing-in-response-to-pollution fishkins is their enhanced detectability and succulence to predators. It may be difficult to document an increased population of glow-fish, though barracuda may eventually show a homey glow in the nether regions.
Posted by: VJB | October 12, 2006 2:26 PM
True. This probably would NOT be a beneficial trait for a small fish.
I don't think they're planning to release the fish into the wild, though. I think an environmental testing lab would collect water samples, bring the samples in to the lab, and pop a fish in each one to see if the fish turned color.
Posted by: Sandra Porter | October 12, 2006 2:33 PM
GFP is amazing. Back in the day, our collaborators used GFP to tag the visual pigments in Xenopus. You could tell (at least in tadpoles), rod and cone morphology quite easily.
Posted by: Deepak | December 13, 2007 10:49 AM
I'm still aching for someone to get the FDA to declare GFP "GRAS".
I've been threatening to make "Glogurt" for years...
Posted by: SMC | December 13, 2007 1:39 PM
The yogurt would have a higher protein content, too!
Posted by: Sandra Porter | December 13, 2007 2:01 PM
If the water contains harmful substances, the fish usually die or produce deformed offspring. Glowing fish could make the assay quicker. If toxic compounds can be detected more quickly, then rivers, streams, and lakes could be protected more quickly.
This is great! A 21st century variation on the canary in the coal mine, only ours are red instead of yellow! LOL! Since pollution detection can be so much quicker this way I wouldn't be surprised if we end up seeing these little fishies being mandatory in waterways in the future!
Dave Briggs :~)
Posted by: Dave Briggs | December 14, 2007 11:37 AM
Very interesting article.
As an editor for The Issue, a recently launched Blog Newspaper we've featured this in today's Science and Health Section. You an find a brief excerpt and a link back at www.TheIssue.com
Cheers
Jean-Baptiste
Science&Health | The Issue
www.TheIssue.com
Posted by: Jean-Baptiste Cossart | December 14, 2007 12:12 PM
According to Wikipedia:
In 1999, Dr. Zhiyuan Gong and his colleagues at the National University of Singapore extracted the green fluorescent protein (GFP) gene from a jellyfish that naturally produced bright green bioluminescence. They inserted the gene into the zebrafish genome, causing the fish to glow brightly under both natural white light and ultraviolet light. Their goal was to develop a fish that could detect pollution by selectively fluorescing in the presence of environmental toxins. The development of the always fluorescing fish was the first step in this process. Shortly thereafter, his team developed a line of red fluorescent zebra fish by adding a gene from a sea coral, and yellow fluorescent zebra fish, by adding a variant of the jellyfish gene. Later, a team of Taiwanese researchers at the National University of Taiwan, headed by Professor Huai-Jen Tsai, succeeded in creating a medaka (rice fish) with a fluorescent green color.
Posted by: David | December 15, 2007 4:22 PM
If the water contains harmful substances, the fish usually die or produce deformed offspring. Glowing fish could make the assay quicker. If toxic compounds can be detected more quickly, then rivers, streams, and lakes could be protected more quickly.
Posted by: geciktirici | December 23, 2007 4:23 PM