

These glowworms are the larvae of fungus gnats of the genus Arachnocampa, with eight species endemic to Australia and a single species found only in New Zealand 2. 1), the molecular details of glowworm bioluminescence have remained elusive. In contrast to luminescent beetles such as the firefly (Coleoptera), whose bioluminescence has been well characterised (reviewed by ref. Glowworms are found in New Zealand and Australia, and are a major tourist attraction at sites located across both countries. These findings show that luciferases can evolve independently from the same family of enzymes to produce light using structurally different luciferins. A candidate luciferin structure is proposed, which needs to be confirmed by chemical synthesis and bioluminescence assays. However, the luciferin substrate of this enzyme is produced from xanthurenic acid and tyrosine, and is entirely different to that of the firefly and known luciferins of other glowing creatures. The purified luciferase enzyme is in the same protein family as firefly luciferase (31% sequence identity). We have isolated and characterised the molecular components of the glowworm luciferase-luciferin system using chromatography, mass spectrometry and 1H NMR spectroscopy. The glowworm is evolutionarily distant from other bioluminescent creatures studied in detail, including the firefly. The New Zealand glowworm, Arachnocampa luminosa, is well-known for displays of blue-green bioluminescence, but details of its bioluminescent chemistry have been elusive.
