Illuminating the Secret of Glow-in-the-Dark Mushrooms: Scientists now understand what makes bioluminescent mushrooms glow, which may pave the way to new possibilities for harnessing fungal bioluminescence in analytical and imaging technologies. Bioluminescence is a highly conserved phenomenon that exists in a wide range of organisms; there are roughly 80 different known species of bioluminescent fungi alone scattered across the globe. In most cases, light emission from living organisms occurs when a molecule called luciferin and its enzyme partner, luciferase, mix together with energy and atmospheric oxygen, triggering a chemical reaction that produces a very "excited" oxyluciferin, which releases light energy in order to "calm down" to its ground state. The luciferin-luciferase pathway has been well-characterized in bioluminescent insects, bacteria and some marine animals -- but not in fungi. Here, Zinaida Kaskova and her team were able to elucidate the molecular components involved in the fungal luciferin-luciferase pathway, leading to the discovery of the fungal equivalent of oxyluciferin by analyzing extracts of Neonothopanus gardneri (a fluorescent mushroom native to Brazil), and Neonothopanus nambi (a poisonous mushroom found in the rainforests of southern Vietnam). The authors suggest that fungal luciferase may be "promiscuous," potentially able to interact with multiple derivatives of fungal luciferin, leading to changes in intensity and color of emission.