6 SURVEY OF LUMINOUS ORGANISMS 



In an organism with extracellular luminescence such as the ostracod 

 crustacean Cypridina, gland cells are filled with the finished secretion 

 to be extruded to the sea water by the contraction of muscles. In 

 such a case we may expect the principal luminous substances directly 

 concerned with light production to be present, with a minimal amount 

 of precursor. The reaction products form in the sea water. Cypridina 

 does possess the simplest chemical system thus far investigated, one in 

 which the only recognized substances are oxygen, a heat stable, dia- 

 lyzable, oxidizable substance, luciferin and a thermolabile enzyme, 

 luciferase, specific for the light-emitting oxidation of luciferin in 

 aqueous solutions. In the Cypridina gland, the luciferin and luciferase 

 are manufactured in separate gland cells. Since the chemistry of lumi- 

 nous bacteria, of the firefly, and of Cypridina is individually repre- 

 sented in this conference, a discussion of the accessory factors involved 

 in bacterial and firefly luminescence will be found in the appropriate 

 chapter. Studies on luciferase kinetics, similar to those made by Chase 

 ( 1946-52 ) with Cypridina luciferase, should be extended to other 

 organisms. 



The ability to demonstrate the luciferiu-luciferase reaction according 

 to the method described in the explanation of Table I is presented 

 in column 5. In addition to Cypridina, fireflies, and bacteria, only the 

 marine fireworm of Bermuda {Odontosyllis enopla), the deep sea 

 shrimp (Systellaspis and Heterocarpus), and the fresh water limpet* 

 {Latia neritoides) , of New Zealand, have been reported as positive 

 for a luciferin-luciferase reaction. 



Although firefly biochemistry will be considered in another chapter, 

 it must be pointed out that in the firefly luminescent system, adenosine 

 triphosphate (ATP) is an important accessory substance. This can 

 be demonstrated by the fact that a cold water extract of the luminous 

 tissue of the firefly allowed to stand until all light disappears, will 

 again luminesce when ATP is added (McElroy, 1947, 1951). A sys- 

 tematic test of similar ATP action in other luminous organisms has 

 been made by Harvey and Haneda (1952) and Haneda and Harvey 

 ( 1954) and is included, together with later tests, in Table I, column 6. 

 The importance of ATP in luminescent reactions appears to have 



• According to Bowden (1950). 



