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  • Sherin Thomas

Living Lights and the Allure of Bioluminescence

Written for Ours, Scientifica for the NUS Science Journalism Club

It was a brilliant sight.

Shimmering jewels pulsed and twinkled against the black void of space.

As the astronaut John Glenn stared at the enveloping darkness from the window of his space capsule during the first orbital spaceflight mission in 1962, he wondered how the “luminous objects that glowed in the black sky” resembled the friendly twinkles of the fireflies that lit up the summer nights he spent in Ohio, USA (Rosenblatt, 1998). Walking through the woods and chancing upon these dancing bioluminescent insects, one can easily envision a scenario in which our ancestors in the Stone Age tucked these creatures between their fingers to guide them through the encroaching darkness of the night.

Mankind’s fascination with bioluminescence, or the cool glow of other living creatures, has been recorded throughout history. Even though we know that an extraordinary number of creatures are bioluminescent, from mushrooms to sharks to microscopic dinoflagellates, the secret to the bioluminescence of these creatures remained shrouded in mystery until the turn of the last century until a team of scientists deciphered the workings of bioluminescence (Langlois, 2019). A mere three or four decades later, the living lights of these bioluminescent creatures are pervasively used by biomedical researchers to light up the interior of cells and tissues that are still alive. This ability to light up the darkest chambers of cells using the “fires” from these living lights have now opened up a living terra incognita that was previously hidden from the sight of even the most formidable scanners and microscopes (Langlois, 2019). Exploration of this vast chamber is every bit as tantalising as the very revolution that led to the discovery of bioluminescence. Fluorescent proteins are now a crucial part of uncovering the molecular doctrines that govern cellular processes and are actively used to fight diseases such as AIDS, cancer, Parkinson’s disease, and even to track viral infections (Dybas, 2019). And there are yet innumerable other untapped potential applications of bioluminescence.

And yet, prima facie, the aforementioned narrative of the revolution of bioluminescence is akin to many other narratives spun about the revolutions of countless other scientific discoveries in its ambition and its insistence about the sanctity of scientific pursuits. Man penetrates deep into the secrets of nature and demystifies nature’s mechanics to discover some physical law, mathematical formula, chemical equation, DNA sequence, protein structure, biochemical mechanism, or biological description to encapsulate nature’s enigma. Man satisfies his Promethean hunger to seek that which enriches humanity and man translates this discovery in a seemingly benign manner to produce a fantastical application that not insignificantly alters the course of humanity. Nature is likened to an unyielding master with whom all secrets selfishly lay and from whom these secrets must pried from. This is the myth of Prometheus, the titan who stole the “fire” of gods and presented it as a gift to man, marking the birth of a civilisation.

This myth, however sweet and alluring, is a misleading representation of our relationship with nature. To decode this myth of scientific discovery will yield a more accurate representative image of our connection to nature and I shall attempt to do so in this essay using the example of bioluminescence.

Under the earth there is a great grotto, or seven grottos under one another, in which the souls of the dead dwell, and where in place of the sun and moon, only rotten trees give out a dim light (Harvey, 1957).

The above is one earliest accounts of bioluminescence recorded in human history in which luminescence of decayed wood was credited as the abode of the dead in the folklore of Yenisei Ostiaks. Light has always occupied a place of high importance in the stories of many religions and folklores of many cultures and the origin of light is often included in myths about the creation of life. In most instances, light is almost always associated with heat and the luminous glow of light in the absence of heat is indeed a rarity in myths and legends and is often imbued with supernatural significance (Harvey, 1957).

It is among animals, however, that records of luminescence are mostly found. Records of fireflies and glow-worms have been found in several sacred books in India and China. For instance, in the Upanishads, which is part of the Brahmanas which is the priestly dicta of the Hindus, we find the following reference:

Fog, smoke, sun, fire, wind, Fireflies, lightning, a crystal, a moon – These are the preliminary appearances Which produce the manifestation of Brahma in Yoga. (Harvey, 1957)

In this text, we find that fireflies are considered to be spiritual augur of Brahma, the creator god in Hinduism and this suggests luminous creatures portend the presence of divinity. To be infused with light, is to be divine or supernatural. The brightness of firefly luminescence is also mentioned in Further Dialogues of the Buddha translated by Lord Chambers from the Pali of Majjhima Nikāya. Sections of this text compare a heretic’s perfection to a gem which shines and sparkles less than the firefly of the night, i.e. it is “less than, and inferior to, a firefly” (Harvey, 1957).

Other accounts from the Historia Naturalis, one of the few texts thought to have survived from the Roman Empire to the modern day and written by the Roman author, naturalist, and philosopher Pliny the Elder, make numerous references to the glow-worm; the luminous mollusc, Pholas dactylus; a luminous medusa, Pulmo Marinus; the lantern fish, Lucerna Piscis; a luminous fungi and a plant that emits a warm glow upon dessication. For instance. Pliny writes in detail about a “fish called the Lanterne”, which he also refers to as Lucerna piscis. He writes as such, “There is a Fish commeth ordinarily above the water, called Lucerna, for the resemblance which it hath of a light or lantern. For it lilleth forth the tongue out of the mouth, which seemeth to flame and burne like fire, and in calme and still nights giveth light and shienth” (Harvey, 1957). Such creatures could possibly refer to jellyfishes which when stimulated to luminesce, might be readily mistaken for a mythical monstrous creatures from the depths of the oceans. These extracts reflect an underlying amazement at the ability of a seemingly inferior creature to produce light with the accompaniment of heat. Other cultures, however, do not share this incredulity for the humble firefly such as the Arabs who named these creatures after a man who was so stingy that he always kindled a fire too small to be of any value to anyone (Harvey, 1957).

Be that as it may, it is evident that for millennia, people have devised rather ingenious applications to harvest the cool glow of bioluminescent creatures, many of which are still undiscovered today. We know, for instance, that in ancient China used the luminescent glow of fireflies to see in the dark hours of the night. There is a story concerning a Chinese government official, Ch’e Yin or Hsien Yin, who lived during the Tsin dynasty and was apparently a diligent but poor scholar who could not even afford to buy oil to light his lamps in the evenings. Instead, Hsien Yin, in his poverty, collected fireflies and used them to continue his studies at night (Harvey, 1957). In another part of the world, Pliny the Elder wrote that a walking stick can be used as a torch by rubbing the “squeezate” of a particular luminescent jellyfish (possibly pelagia noctiluca) onto the end of the stick. As he writes, “Rub a piece of wood with the fish [sic] called Pulmo Marinus, it will see as though it were on a light fire; in so much as a staffe [sic] so rubbed or besmeared with it, may serve instead of a torch to give light before one” (Harvey, 1957). Such torches would undoubtedly be as useful as torchlight or a torch lit by fire to read the gloomiest night. Additionally, it was also observed that the indigenous people of Indonesia used bioluminescent fungi as flashlights in the forest, an observation made by physician Georg Eberhard Rumphius in the 17th century. There are also countless accounts of coal miners who, in the 19th century, filled jars with fireflies or dried fish skin infected with bioluminescent bacteria to explore the dark chambers of mines when fire failed them (as carrying an open flame into a cave risked igniting explosive gas).

It took longer for records of humans using the bioluminescence of other smaller sea creatures such as ostracods to emerge because it took a long while for mankind to be aware of their presence. There are numerous records of early explorers who were seemingly amazed by the “exhalations of fires from the sea”, presumably referring to marine luminescence (Harvey, 1957). These ribbons and specks of “unnatural” luminescence in oceans and seas were also observed by Charles Darwin who noted in his journal:

While sailing in these latitudes on one very dark night, the sea presented a wonderful and most beautiful spectacle. There was a fresh breeze, and every part of the surface, which during the day is seen as foam, now glowed with a pale light. The vessel drove before her bows two billows of liquid phosphorus, and in her wake she was followed by a milky train. As far as the eye reached, the crest of every wave was bright, and the sky above the horizon, from the reflected glare of these livid flames, was not so utterly obscure, as over the rest of the heavens (Harvey, 1957).

The above description of bioluminescence in the sea is closer to poetry than it is to science and, more striking I think, light is made akin to fire as the naturalists before him, even when it is in the water. Such allusions to fire were seen even in ancient Chinese narrations of nautical adventures such as Hai Nei Shih Chou Chi which claims that “ one may see fiery sparks when the water is stirred” (Harvey, 1957).

In 1753, a plausible reason for bioluminescence was proposed by Benjamin Franklin who claimed that a certain kind of “extremely small animalcule” in the seas “may yet give visible light” (Jabr, 2016). His hypothesis was later confirmed by Godeheu De Riville with a microscope. Franklin was right. We now know that the fiery glints ad sparks of the oceans is caused by the luminescence from the “insects” of the oceans, planktons. So vital were these creatures to marine warfare that they were extensively used by some of the world’s most powerful military powers. For instance, stories abound of the Japanese soldiers harvesting a huge number of umihotaru (sea fireflies) who then proceeded to use the cool blue glow emanated from the desiccated bodies of these creatures to read maps and other transcripts (Jabr, 2016). Apart from its use as light-bearers, bioluminescence can also be a nuisance because as navy boats and other vessels pass through streams of bioluminescent planktons, pools of such creatures would stick to the sides of the ships and the luminescence emanating from these creatures would bled through the dark waters and give away the positions of the vessels, often to the detriment of those onboard. In fact, the United States Army is currently attempting to create an aquatic device that can both detect bioluminescence of enemy vessels and evade detection of their own boats (Jabr, 2016).

It is quite evident that mankind’s fascination, or perhaps obsession, with bioluminescence has been pervasive throughout the ages and have not been diluted an iota. But why are so obsessed with the fiery glow of bioluminescent creatures? It isn’t the light that we’re obsessed with. After all, each morning, rays from the sun permeate the land from space as though there were a crack in the sky. The golden waves splashes over the cities and towns; pools silently in the oceans and seas; trickles down dews gathered on the leaves and grass; slips through cracks in forest canopies to the mass of dead leaves on the forest floor. It slips through the pores of our eyes and into the recesses of our minds, illuminating us with the sight of all. And yet, it seems that we cannot get enough of it and with an Icarian rashness, cannot feel close enough to it. Throughout centuries, we have created myths about supernatural entities infused with the cool lustrous glow seen in other living creatures precisely because it is a gift that is denied to us. And thus, we created gods of these creatures and, with a Promethean hunger for the gifts of the gods, sought to steal the “fire” of bioluminescence.

Until we decoded the mysteries of bioluminescence, we tried to harness lights in host of other ways. Our ancestors tamed fire and we now generate light through electricity. We’ve learnt how to create spectacular explosion of colours in the night sky and have erected powerful beacons that cuts through the densest fog and calls to lost ships in the gloomiest night. And yet, none of our contraptions equal the firefly, jellyfish, mushroom, dinoflagellates or planktons in its elegance or intuitive mastery of luminescence. Their unique ability to generate light in a seemingly effortless manner is beautifully interwoven and stitched into the DNA of these bioluminescent creatures. This, to us, is a divine gift, a supernatural power that we have lusted after and hoped to attain to attain equal footing with these “gods”.

Our fascination with bioluminescence finally culminated with the discovery and elucidation of the molecule and chemical process responsible for the rhapsodic glow of bioluminescent creatures. The first Promethean figure who attempted to uncover the mysteries of bioluminescence is Raphaël Dubois, a French pharmocologist who studied the mollusc Pholas dactylus and demonstrated that bioluminescence is the result of the oxidation of certain organic compound, luciferin, by an enzyme (Dybas, 2019). Today, scientists know that bioluminescence, which means “cold light”, is a form of chemiluminescence in which light energy is released by a chemical reaction within a living organism (Editing & Evers, 2013). This reaction involves the light-emitting pigment discovered by Dubois, the luciferin, and an enzyme, luciferase. Like the diversity of species that are capable of emitting bioluminescence, there is a diversity of luciferin/luciferase combinations and there are few commonalities in the chemical mechanism, although it has been observed that the role of molecular oxygen and the concurrent release of carbon dioxide are conserved across many species and bioluminescence reactions. While a slew of scientists worked on elucidating the biochemical mechanism of bioluminescence for years, it fell to a young Japanese pharmacologist Osamu Shimomura to extract luciferin from ostracods and determine the exact molecular structure of the protein in 1955 (Jabr, 2016).

A few years later, in the 1960s, Shimomura began to investigate the unusual chemistry of the luminescent system of the jellyfish Aequorea victoria, which do not exhibit the usual luciferin-luciferase reaction. We know now that instead of a luciferase, jellyfishes of this species make use of another type of protein called a photoprotein to facilitate the function of luciferins (Jabr, 2016). By collecting numerous A. victoria specimens and straining them to obtain the “juice” or the squeezate of the jellyfish, they discovered a specific photoprotein aequorin that releases blue light, even in the absence of oxygen, which may sometimes be absorbed by another protein in the jellyfish, the green fluorescent protein (GFP), which then emits green light in response. After nearly two decades of research, Shimomura had uncovered the peculiar bioluminescence of the A. victoria jellyfishes and thoroughly elucidated the structure of aequorin (Jabr, 2016). He had, metaphorically, shed light on a puzzling phenomenon of nature that had captivated mankind for centuries. Together with Chalfie who demonstrated GFP’s use as a tag for DNA and Tsien’s expansion of the technology, Shimomura won the 2008 Nobel Prize in Chemistry for their work on GFP (Dybas, 2019). Today, these proteins have made important contributions to biomedicine and are indispensable tools in biology and medicine. We can now able to track the molecular waltz of genes and proteins in live cells which were previously hidden from our sight and are able to observe vital processes such as the development of neurons or cancer cells and viral infection of cells.

Recently, the use of “bioluminescent” proteins has opened to commercial possibilities and is now a plaything for bioartists as well. For instance, a French-startup, Glowee aspires to find a cleaner and more sustainable lighting source using genetically-modified bacteria Aliivibrio fischeri encased within a nutrient-filled shell that emanate synthetic blue-green light (Glowee). Another company with slightly less ambitious goals for the usage of these bioluminescent creatures would be the Kickstarter-funded company, BioGlo, which sells unique handheld, hour-glass shaped aquariums filled with hundreds of dinoflagellates (Kickstarter). Dinoflagellates are a type of bioluminescent marine plankton which photosynthesises during the day and absorbs the sun’s light; at night, when you switch off all light and give this aquarium an occasional swirl or shake, the dinoflagellates emit a rhapsodic turquoise light that shines like the “livid flame” or the “fiery sparks of light” once observed by Darwin or earlier naval explorers. And hey, you can do so for only 189.99 dollars (Glowee). What was once exquisite, rare, and beauteous sight that captured the fascination and desires of mankind for centuries can now be sold in bottled glass to the highest bidder. Talk about using the Promethean flame to light a cigarette.

It is easy to have your heart go out to these creatures to which these seas and the oceans were once their abode and are now trapped in small glass bottle for our amusement. Each night, they are awakened from their slumber by some titan who gazes deep into their miniscule ocean and agitates it into a maelstrom. These creatures, in their adventitious misery, then give out an ethereal glow that momentarily satisfies the giant who calmly tosses their world aside as though closing a music box that plays a gentle, melancholic tune which lingers in space long after it stopped playing. They are kept caged for their “magic”.

Or perhaps, we are the misers of this relationship. We seemingly mastered the secrets of these creatures and stolen the fire of these “gods”; we imagine ourselves to be the masters of these creatures and yet, we are still bewitched by these creatures. When we cage these creatures in a glass bottle, there is a temporary sense of possession, of mastery over them. When we decode the secrets to their bioluminescence, we believe that their otherworldly mysteries are ours to behold and use. And yet, the situation couldn’t be further from the truth. Bioluminescence is ubiquitous in our planet, and even more so in the oceans. Scientists currently estimate that the number of known species that are capable of bioluminescence are but a fraction of the actual sum and it may very well be that a vast majority of these creatures lurk deep beneath the oceans and, unable to find the sun’s rays, they generate their own, using the light to hunt for prey, signal for mates, beguile and chase, or to lure and kill. Bioluminescence is a foreign language used by these living lights and it is all around us; they have been a part of nature for eons. The truth is there is supernatural about these creatures; we weave myths around them because they possess a gift that is largely denied to us, just as we do with all other things unknown.

Perhaps that is why the myth of Prometheus is so very alluring to us. It tells of a story of us, humans, against all-powerful, selfish, and perhaps dangerous gods and mythical beings. We live in danger, and thus, for survival, we have to steal the “fire” of these gods, and demystify the secrets of these beings. It is us versus them. And that is why, perhaps with little gratitude, we adapted the transcendent, almost unearthly gifts of these glowing beings and used them for our own. We borrowed the beacons of these living lights and uncovered knowledge of our own biology and that of other creatures, which we might never have been able to uncover otherwise. Borrow. That is all we can do. Instead of “stealing” the torch of fire, we simply borrowed it for our own use. It isn’t mastery over other creatures; it is a harmonious union between man and nature. To this day, as we cup the enchanting fireflies in our hands or stare longingly at the noble jellyfish or delight at the gentle ostracods, it is perhaps with a hidden amusement or wonderment that we inhabit the earth with these creatures and there is yet more learn.

Works Cited

  • Dybas, L. C. (2019). Illuminating New Biomedical Discoveries: Bioluminescent, biofluorescent species glow with promise. BioScience , 487–495.

  • Editing, E., & Evers, J. (2013, June 13). Bioluminescence. Retrieved July 30, 2020, from National Geographic: https://www.nationalgeographic.org/encyclopedia/bioluminescence/

  • Glowee. (n.d.). Overview. Retrieved July 31, 2020, from Glowee - Meet an Unreasonable company: https://unreasonablegroup.com/companies/glowee/#overview

  • Harvey, E. N. (1957). A history of luminescence from the earliest times until 1900. Philadelphia: American Philosophical Society.

  • Jabr, F. (2016, May 10). The Secret History of Bioluminescence. Retrieved July 30, 2020, from Hakai magazine: https://www.hakaimagazine.com/features/secret-history-bioluminescence/

  • Kickstarter. (n.d.). BioGlo - The Bioluminescent Aquarium. Retrieved July 31, 2020, from Kickstarter: https://www.kickstarter.com/projects/microbes/bioglo-living-ocean-light

  • Langlois, J. (2019, December 5). How Studying Bioluminescent Creatures Is Transforming Medical Science. Retrieved July 28, 2020, from Smithsonian Magazine: https://www.smithsonianmag.com/science-nature/how-bioluminescent-creatures-are-transforming-medical-science-180973690/

  • Rosenblatt, R. (1998, August 17). John Glenn: A Realm Where Age Doesn't Count. Retrieved July 25, 2020, from TIME: http://content.time.com/time/magazine/article/0,9171,988917,00.html



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