Worm Breeder's Gazette 5(2): 14b

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

Purines and Pyrimidines in the Growth of Caenorhabditis elegans

E.G. Platzer, J. E. Eby

Caenorhabditis n at 20 C in thin films of 
Caenorhabditis briggsae Maintenance Medium (CbMM).  The medium was 
supplemented with  -sitosterol and cytochrome c.  Growth of C.  
elegans was reduced significantly when purines and pyrimidines were 
removed from CbMM.  Although the growth rate of C.  elegans was 
reduced by the absence of exogenous purines and pyrimidines C.  
elegans grew continuously in axenic cultures for more than 100 
generations.  The growth rate was restored only by the replacement of 
adenosylic acid (AMP).  The optimum concentration of AMP was 0.5 to 1 
M, whereas 5 M inhibited the growth of C.  elegans.  Adenosine and 
adenine were equivalent to AMP in restoring the growth of C.  elegans.  
Other purines (guanosine monophosphate, guanosine, guanine, inosine 
monophosphate, inosine, or hypoxanthine) and pyrimidines, (cytidylic 
acid, uridylic acid, and thymine) were ineffective in restoration of 
the growth.  These findings suggest that C.  elegans has adequate 
endogenous biosynthesis of pyrimidines but the purine biosynthesis is 
inadequate to achieve maximal growth of the nematode in CbMM.  The 
lack of effect by exogenous purines other than the adenine group 
suggests that hypoxanthine (guanosine) phosphoribosyltransferase is 
absent in C.  elegans.  --Department of Nematology, University of 
California, Riverside, CA 92521.