Worm Breeder's Gazette 9(1): 55

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.

Ascaris Antibodies Cross React with C. elegans P-granules

K. Bennett

As an initial means of investigating germ cell determination in 
Ascaris des, I have begun to produce monoclonal 
antibodies using homogenates of fertilized Ascaris eggs as the 
immunogen.  Two spleens of immunized C57B1/6 mice were fused with P3.
653 myeloma cells.  Supernatants of the resulting 193 hybridoma 
colonies were first screened by indirect radioimmune assay for binding 
to egg homogenates.  The 83 positive cell lines were frozen away, 
while their hybridoma supernatants have been further characterized.  
It was brought to my attention that phosphorylcholine is 
immunodominant in nematode infections (Jour.  of Immunol.(1985) 
134:1172-1177.  and Jour.  of Immunol.(1976) 116 1105-1109.) Therefore 
the positive antibodies were then screened in a competitive binding 
assay against soluble phosphorylcholine.  Almost half of the cell 
lines tested, (and most of the 'best binders' in the solid phase assay)
, could be competed with phosphorylcholine and are tentatively 
identified as being directed against this molecule.  As a 
collaborative effort with Susan Strome, the 43 remaining hybridomas 
were screened on C.  elegans and Ascaris eggs which had been cracked 
in liquid nitrogen and fixed with methanol and acetone (Strome and 
Wood, (1982) P.N.A.S.  79 1558-1562.).  We found that Ascaris egg 
membranes are not permeablized by this technique (as monitored by the 
lack of binding with an alpha-tubulin antibody), however in screening 
the C.  elegans embryos, 8/43 supernatants from the Ascaris antibodies 
bind to the germ cell P-granules of C.  elegans with varying degrees 
of intensity.  Supernatants from another 5/43 of the Ascaris lines 
bind to other tissues in the C.  elegans embryo, including the cuticle 
and what appears to be nerve.  The rest of the Ascaris antibodies were 
negative for binding C.  elegans embryos.  We are currently working on 
means to permeabilize the Ascaris egg membranes to determine the 
specificities of these antibodies in Ascaris.