Fooled by a Science Magic Trick – GloFish
I am fascinated by fluorescent and light-producing critters. Who hasn’t been fascinated by a field of fireflies? The ocean is host to many fluorescent animals – jellyfish, bacteria, coral and fish, to name a few. Scientists study these animals to try to understand the purpose behind the fluorescence, but even without a purpose, the bright, vivid colors capture the imagination.
Scientists are also very good at exploiting these naturally found phenomenon for use in the laboratory. The proteins in fireflies that produce light are used often in the lab. One of the most common uses is to measure how much of a particular protein is found in a cell. The more protein there is, the more light there will be. It makes it very easy to measure protein amounts.
When I was a graduate student, green fluorescent protein (called GFP) became all the rage. GFP is a small protein found in jellyfish that naturally fluoresces in a bright green color. The neat thing about this protein is that it is very hardy and can be hooked up to other proteins and still fluoresce. GFP is used to look at proteins within a living cell – with the right microscopes you can actually watch proteins move around inside a cell. In the following YouTube video, GFP was hooked up to a protein in vaccinia virus (the small pox vaccine). The green dots moving around inside the cell (kind of outlined in red) are real virus particles.
This past weekend we took the kids to the Mystic Aquarium in Mystic, CT. One of the exhibits was filled with fluorescent fish of all colors. As usual, I was fascinated by this thrilling display by nature – until I read the plaque above the tank that explained that these weren’t natural fish. The fish in the tank and the fluorescent fish sold in many aquarium stores (the ones in which the fluorescence is throughout the whole fish body) are genetically-modified (GM) fish. Fish eggs were injected with DNA that makes the GFP protein (green fish) or other fluorescent proteins to make a rainbow of GM fish.
I had to find out more about this.
Before you start thinking that us scientists run around making Frankenbeasts for fun all day, I would like to tell you that these fish were first made for a scientific purpose.
In 1999, Dr. Zhiyuan Gong at the National University of Singapore wanted to use fish to detect environmental toxins in water. He set out to construct fish that would glow if they were swimming in water that contained toxins. A first step in this research was to try to make a fish that glowed all the time. He was very successful!
His success attracted the attention of companies that sell ornamental fish for aquariums. Thus, the GloFish industry was born. Starting with green fish, other fluorescent proteins have been used to make red, orange-yellow, blue, purple and pink fish.
GloFish are the first GM animals sold commercially as pets. In a later post I might tackle discussing GM animals, however I did want to mention that the development and sale of GloFish have met with controversy. Australia, Canada and Europe prohibit the sale of any GM fish. In the United States, GloFish are illegal in California.
I will probably just stay away from them for now since they fooled me.