Bioluminescence and Nature's Glow

Conan Doyle was a great aficionado of Scotland, Edinburgh, and St Andrews, having lived, studied, and mastered golf here. In the book The Hound of the Baskervilles, Doyle writes about a spectral hound that luminesces in the night; the luminescence in this standout novel is the smearing of white phosphorus on the hound. White phosphorus glows green when exposed to the air, through a process called chemiluminescence, hence the glow of the dog! 

The reality of white phosphorus is that any biological organism coated in this substance would suffer horrendous chemical burns and not be long for this world. This, of course, gives a slight flaw to what is otherwise one of the better Sherlock narratives. If Conan Doyle were to visit St Andrews today, he would be able to plump for other, less toxic ways to make the great dog in his story glow; bioluminescence would be Mr Doyle’s go-to option in 2025.

Bioluminescence is a chemical reaction that takes place within cells of specific organisms. It is one of nature's unique phenomena and can be easily observed in things such as fireflies and deep-sea creatures. The chemical reaction that generates light energy relies on three key components: oxygen, luciferin, and luciferase.

Bioluminescence is one of nature's convergent evolution complexities; multiple different organisms have evolved bioluminescence independently of each other, going from plankton, which can appear to make the sea glow under certain circumstances, all the way to some types of fungi.

As with all things evolution-based, a selective force has been at work, and bioluminescence is providing a competitive advantage, be it to avoid predators or to communicate between members of the same species; flashing a signal to each other in the pitch black is one of the pretty limited options you have for communicating in such a difficult environment.

In Japan, there is a bay that you can visit, where at certain times of the year, you can see a squad of squid glowing it up for each other, in what is believed to be a major breeding site for the aptly named firefly squid!

If you are lucky enough to go to the Maldives, you can take a dip at night, and possibly swim through a bloom of bioluminescent plankton — pretty much like switching on a vivid green-blue light show. There have even been the odd sighting of “glow-in-the-dark” algae blooms off the coast of St Andrews, so when you are next out for a dip, weather and sea conditions permitting, you might just find yourself in the middle of your own glow.

Bioluminescence is not a natural phenomenon for the majority of animals and certainly not mammals, but science is now on hand, and genes like luciferase have been successfully inserted into a range of animals/mammals with a variety of different outcomes and uses.

Being used at the cutting edge of studying tumours, their growth patterns, and understanding drug uptake, and even amazingly being able to help doctors and nurses track progression of infections in patients, all through looking for the telltale glow!

Scientists have now harnessed certain bacteria (giving them the “glow” genes) to use them as environmental indicators. With the right bacteria, they have been able to harness bioluminescence to act like a large visual green-blue warning glow to signal the presence of certain pollutants in the environment. 

Some research is even currently on the go using certain classic houseplants to try and get them to “glow” when they need to be watered […] just think of the millions of plants around the world that would no longer suffer in silence!

The pace of research into bioluminescence is bounding forward, to date, science has produced glowing mice, fish, rabbits, rats and even pigs If you are one of the Molecular Biology students here in St Andrew, just think,— with right CRISPR system and a sample of glowing algae from St Andrews Bay, you could take the next big leap in Bioluminescence. By putting St Andrews back on the map alongside one of its famous visitors, Conan Doyle, you might even inspire his long-awaited sequel, The Bioluminescent Baying Hound — something worthy of a final year thesis, I feel.

Image from Wikimedia Commons