Recent Studies on the Chemistry 

 of Cypridina Luciferin* 



Frederick I. Tsuji, Aurin M. Chase, and E. Newton Harvey 

 Biological Laboratories, Princeton University, Princeton, New Jersey 



Historical Introduction 



The luminescent system in the marine ostracod crustacean Cypridina 

 hilgendorfii is one of the simplest among luminous animals. Only lu- 

 ciferin, luciferase, and dissolved oxygen appear to be necessary for 

 light production in aqueous solution. In this respect the Cypridina 

 system differs from that of the firefly, where luciferin, luciferase, 

 adenosine triphosphate, magnesium ions and oxygen are all essential 

 ( see McElroy and Coulombre, 1952, and Hastings, McElroy and Cou- 

 lombre, 1953, for latest results). 



Structurally, the luminous organ of Cypridina, the submaxillary 

 gland, is also simple, made up of elongated gland cells, whose contents 

 are squeezed into the sea water through individual openings on the 

 tip of the upper lip by contraction of muscle fibers. Observation of 

 the living animal indicates that two varieties of granules pour out of 

 the submaxillary gland, one large (diameter about 10 ix) and yellow, 

 undoubtedly luciferin, and another small (diameter about 2 fi) and 

 colorless, probably luciferase. Both types of granules dissolve on meet- 

 ing the sea water, and at the same time the luminescence appears 

 (see Harvey, 1952, for details of gland structure). 



* This research has been supported in part by a grant from the National 

 Science Foundation, in part by a contract between the Office of Naval Re- 

 search, Department of the Navy, and Princeton University, NR 165-167, 

 and in part by funds of the Eugene Higgins Trust allocated to Princeton 

 University. 



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