Worm Breeder's Gazette 8(3): 45

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.

More Studies of the Cross-Reactivity with C. elegans of Monoclonal Antibodies Directed Against the Drosophila Nervous System.

J. Yuan, H. Ellis, R. Horvitz

As an initial step toward the identification and characterization of 
macromolecules involved in the development and functioning of the C.  
elegans nervous system, we have been screening two sets of monoclonal 
antibodies directed against the Drosophila nervous system for cross-
reactivity in squashed whole mounts of C.  elegans (Newsletter, Vol.  
8 No.  1).  Six of 17 antibodies from the collection of Lily and 
Yuhnung Jan of UCSF stained C.  elegans.  Of these six, three stained 
the nervous system; these three also stained non-neural tissue, such 
as the gonad.  The other three antibodies stained sperm, and one of 
them also stained eggs and muscle.  From the collection of Seymour 
Benzer of Cal Tech, 62 of 153 antibodies cross-reacted with C.  
elegans.  Fourteen of these antibodies stained the nervous system, and 
all 14 also stained non-neural cells.  Three of these 14 antibodies 
stained the nuclei of all cells but sperm.  (These three antibodies 
also stain nuclei in Drosophila.) The other 48 antibodies stained a 
variety of non-neural cells.  Twelve stained sperm, and two of these 
12 seemed to be sperm-specific.  Eighteen stained muscle, and all 18 
also cross-reacted with other structures.  Eleven stained eggs and 
other tissues.  Seven stained a cage-like structure, probably the 
spermatheca, near the uterus in hermaphrodites.  Three of these seven 
appear to be spermatheca-specific.  One antibody specifically stained 
vesicles in the male vas deferens.
Thus, only 17 of the 170 antibodies examined stained the nematode 
nervous system, and none of those that did was obviously specific for 
a subset of neurons.  This observation can be contrasted with other 
studies of the interspecific cross-reactivity of these antibodies.  
For example, approximately half of the Benzer collection antibodies 
react with the human central nervous system, and these antibodies show 
a wide variety of specificities for particular human neuron types.  
One possible interpretation of these apparently contrasting results is 
that these monoclonal antibodies recognize determinants that are 
widely distributed both among species and among cell types within a 
species and that the apparent degree of specificity seen may in 
essence be a reflection of the diversity and complexity of the target 
tissues, e.g., of the fact that the human nervous system is 
substantially more complex than is that of C.  elegans.