Join us for the seasonal feature Luminescence: A Celebration of Aquatic Light – on now through January 22, 2013.
Water jellies (Aequorea sp.) don’t have brains, but they’re helping to advance medical science. Forget synthetic chemicals – scientists in the field of biomedical research are using technology inspired by natural proteins discovered and isolated from this jelly.
Found in the northeast Pacific Ocean, water jellies and can be seen off the coast of B.C. Although their ethereal, see-through bodies can be seen at the surface of the water, they can also swim deeper in the water column. Here, blanketed in darkness, an interesting phenomenon occurs.
Water jellies can produce bioluminescence. This is the ability of a living organism to make light within its body through a chemical reaction. On land, you might see fireflies glow. In the ocean, bioluminescence is widespread and is found in a wide cross section of living things from bacteria to fish. The water jelly’s light organs are found along the rim of its bell.
The bioluminescent light produced by the water jelly’s protein aequorin (when it reacts with calcium) is actually blue, but the water jelly glows green because it has an additional protein in its light organs called the green fluorescent protein (GFP). This protein produces fluorescence, which occurs when we shine one colour of light (usually UV or black light) on a protein or organism and see another colour come out (in this case, green).
Scientists are not sure why the water jellies “light up.” They don’t appear to flash at one another, nor do they have their light constantly “on” in the dark. The only time scientists have seen them light up using bioluminescence is when one has been physically disturbed.
Regardless of the mystery behind why the water jelly lights up, aequorin and GFP have played an important part in medical science. In the ‘60s, scientists were able to isolate these two proteins, and GFP has since proven useful as a fluorescent marker. Essentially, scientists can now use GFP to mark cells in a human or animal body, in a plant and even in a virus (these cells will glow under UV light). GFP has already been used to tag cancer cells, and will continue to play an important part in new medical discoveries.
In 2008, the GFP pioneers who made the discovery about this very important protein were awarded the Nobel Prize in chemistry.
Just think – this modest marine animal has the potential to save lives.
See them fluoresce under UV light below. The green glow you see is from the GFP in the light organs – no bioluminescence is occuring in this video.