Worm Breeder's Gazette 9(1): 52

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.

Differences in adult surface antigens between "wild-type" strains of C. elegans

K. Chin and S. Politz

At the last C.  elegans meeting, we reported that rabbit antibodies 
prepared against adult cuticle proteins bind to the surface of live 
adults and can be rendered adult-specific (free of L4-cross-reacting 
antibodies) by pre-adsorption with saturating numbers of live L4's.  
These antibodies were elicited by an immunogen mixture derived from 
the N2(Bristol) strain.  We have tested twelve different C.  elegans 
strains for the presence of the adult-specific antigen class 
recognized on the N2 surface.  For immunofluorescence staining of each 
strain, approximately 150 worms of mixed stages were incubated with an 
amount of adult-specific antibody sufficient to saturate binding of 
150 N2 adults.  After a second incubation with FITC second antibody, 
worms were spread onto 2% agarose-0.9% NaCl plates and viewed under a 
dissecting microscope equipped with FITC optics.  The number of 
fluorescent vs non-fluorescent adults was scored; no larvae were 
observed to fluoresce.  Each strain showed a characteristic fraction 
of antigen-positive (srf+) individuals.  While N2, as expected, scored 
highest (>95% srf+ adults), and eight other strains (PA-2, GA-1, GA-2, 
AB-1, CL-2A, GA-S, AB-3, and Bergerac FR) could be characterized as 
'intermediate' (>40% srf+ adults), three strains (PA-1, DH424, and 
Bergerac BO) were essentially antigen-negative (<5% srf+ adults).  
Because the phenotypic difference between N2 and PA-1, DH424, or 
Bergerac BO is clearcut, we are analyzing the genetic differences that 
account for the observed surface antigenic differences by crossing N2 
marked hermaphrodites with PA-1 or DH424 males.  So far, in such a 
cross between unc-4(e120) and PA-1 we have shown that the antigen-
negative phenotype is dominant in the F1; i.e., F1 selfs are srf+, but 
F1 outcross are srf-.