The story of glowing animals (or any other living thing) started with a man by the name of Osamu Shimomura, who was so passionate about science, that neither the bombing of the city he lived in during World War II, Nagasaki, nor the lack of opportunities for education could stop him from practicing science and making things glow.
To be more accurate, the story starts with the first naturally occurring organisms with the ability to emit light - some bacteria hundreds of thousands years ago deep down in the prehistoric oceans.
Why do things glow?
Although this is a very good question, the answer is in many cases still unknown. It’s easy to assume that marine creatures such as jellyfish glow, because it’s dark deep down in the oceans. We also know, that some animals glow to attract prey or the opposite sex. An interesting example of this is a female of an insect species that is able to emit light resembling another, smaller species, which attracts the male of the smaller species, and then guess what, she eats him!
But what’s more important to our story is, how we can make things glow, and also our need for glowing animals.
The discovery of GFP
This brings us back to our Japanese hero, professor Shimomura, who was the first person to help people make things glow. And he did this by extracting a certain type of protein, called aequorin from a jellyfish species - Aequorea victoria. Not much, you think? Oh, I forgot to mention that to extract 150 miligrams of this protein he needed 2.5 tons of jellyfish! And what’s more, the protein didn’t want to glow in his lab.
So, after countless experiments with no results, the frustrated Shimomura poured the protein into the sink, and guess what - just before disappearing, the protein shone a little, and Shimomura found out that it simply needed sea water to glow - the sink he dumped the protein into was the same one where they poured dirty water from the aquarium in the lab.
But his troubles did not end there. Next, he found out that although the protein glows blue, the jellyfish itself emits a green light. Why, you ask? Because in the jellyfish, aequorin gives its energy to another substance, which glows instead. And this substance has been helping scientists in countless ways ever since - it’s called green fluorescent protein, or GFP for short.
That’s nice but...what is it good for?
Well, countless things.
Firstly, you can make a certain structure in an organism more visible, or you can see where exactly this structure, or a type of cell occurs, when it glows. The first experiment of this kind was
performed by Martin Chalfie who made the neurons of a tiny worm-like animal called Caenorhabditis elegans glow green, and whose article has been quoted numerous times.
You can also find similarities between different species. There is, for example, a green-glowing cat used to study HIV - cats have their own form called FIV - feline immunodeficiency virus.
Then, there is a group of people designing plants to replace street lamps!
Or, just for fun. Transgenic glowing fish are being sold in the United States - just because they are pretty. You can buy them for 5 - 7 dollars.
Why just green?
We are talking mostly about green because the original GFP was green, as its name says. But nowadays the possibilities are limitless. You can have a glowing protein of any colour you desire and
the man behind this is Roger Y. Tsein, who designed various colours from the original GFP by changing it’s aminoacids, and also Douglas Prasher who was the first man to clone GFP and without whom
this wouldn’t be possible.
So nowadays, you can have an animal glowing any colour you want - the tricky one was red, because it turned out to be toxic, but now it’s made from corals.
To conclude, I would like to add that Shimomura, Chalfie and Tsein were awarded with a Nobel prize for chemistry in 2008. Douglas Prasher was not included since the Nobel prize can be shared by maximum three people.
I would also like to add, that although this might not seem like such a big deal to most of you, genetic engineering is nowadays a big part of our world. Genetically modified organisms are used in many more ways than you can imagine, and GLOWING genetically altered organisms stand behind most of the discoveries in molecular science in the last decade.
A little FAQ for those who might be interested:
Q: Can I buy a glowing pet?
A: Here and now...no. If you moved to the US, you could buy glowing fish. Although, if you wanted to ship them all the way here, you would pay a lot of money and the paperwork would be endless. Then, you might be able to buy a mouse from some university where it’s no longer needed, but the price would be somewhere around 30, 000 euros.
Q: Can I make my pet glow myself?
A: In theory, yes. But you would have to study some biology (I don’t mean the high school level, though) and rob a laboratory. Then you can start thinking about creating some glowing organisms…
Q: Can I glow???
A: Wait for me to finish the university and we can make a deal :-). Just kidding. In theory, it is possible to alter a human genome too but for ethical reasons you can not.
by Daniela Kročianová
Year 1, Issue 3