Biochemistry of 



Firefly Luminescence 



W. D. McElroy and J. W. Hastings 



McCollum-Pratt Institute and Department of Biology, Johns Hopkins 



University, Baltimore, Maryland, and Department of Biological Sciences, 



Northwestern University, Evanston, Illinois 



Judging from the extensive literature on fireflies and glowworms it 

 is apparent that these luminous forms have excited the interest and 

 imagination of scholars and laymen alike. The folklore, history, and 

 scientific accomplishments connected with these luminous forms have 

 been reviewed in detail by Harvey (1952). The first definitive experi- 

 ment regarding the nature of the components necessary for light 

 production was reported by Dubois in 1885. He found that the lumi- 

 nous organs of Pyrophorus, a luminous beetle, would cease to emit 

 light if immersed in hot water. He observed, however, that a cold 

 water extract which had ceased to luminesce could be stimulated to 

 emit hght by adding the hot water extract. On the basis of this type of 

 experiment Dubois proposed the theory that there was, in the hot 

 water extract, a substance stable to heat which was destroyed during 

 its luminescent oxidation through the action of a catalyst present in 

 the cold water extract. He named the heat stable material luciferin 

 and the enzyme which catalyzed its oxidation luciferase. This observa- 

 tion which has been greatly extended and clarified by Harvey and 

 associates is the classical luciferin-luciferase test which is routinely 

 made on all new luminous forms discovered by workers in this field. 

 From a comparative biochemical viewpoint the dissipation of 

 energy in a biological system in units of 40-60 kcal appears quite 

 unique. Most of our information on the generation and transfer of 

 useful energy in biological systems suggests that the process takes 



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