Chemistry of Nematocyst 



Capsule and Toxin 



of Hydra Uttoralis 



Edward S. Kline^' - 



Biochemistry Branch, Arrived Forces Institute of Fathologij, Washington, D.C. 



Nematocysts are highly organized, complex, intracellular struc- 

 tures. They are vital for the survival of the animal. Much of the 

 synthetic activity of the hydra is directed toward production of 

 the functional nematocyst, a structure that is quickly lost in the 

 course of its function in captiuing the live animals upon which the 

 hydra feeds. About 25% of the tentacle nematocysts are lost each 

 time H. Uttoralis eats a meal of Aiicmia; these are rapidly replaced 

 in about 48 hours from the store of differentiating nematocysts 

 in the body (11). Because of this continual and active develop- 

 mental process, nematocysts are an excellent system for chemical 

 studies of biosynthetic and morphogenetic processes. It is toward 

 an understanding of these processes that we hope to apply, as it 

 accumulates, information regarding the chemical structure of these 

 interesting organoids. 



^ Studies of the author on the nematocyst capsule were carried out in collabora- 

 tion with Dr. H. M. Lenhoff, Howard Hughes Medical Institute, Miami, Florida; 

 studies on the succinoxidase inhibitor were carried out in collaboration with Dr. 

 V. S. Waravdekar, Chief of the Biochemistry Branch, Armed Forces Institute of 

 Pathology; studies on serotonin were carried out in collaboration with Dr. H. Weiss- 

 bach, Laboratory of Clinical Biochemistry, National Institute of Health, Bethesda, 

 Maryland. 



2 Present address: Department of Chemistry, Indiana University, Bloomington, 

 Indiana. 



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