Worm Breeder's Gazette 7(2): 18

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.

Minor Structural Proteins of C. elegans Muscle

R. Francis, R.H. Waterston

We have sought to identify minor structural proteins of C.  elegans 
muscle with the eventual aim of characterizing genes encoding them.  
For this purpose, antibodies are being raised to minor bands present 
in extracts of broken cuticles with muscle fibrils still attached, 
prepared by limited French press shearing and repeated low-speed 
sedimentations in low ionic strength buffer containing nonionic 
detergent.  By polarizing and electron microscopy the bodywall 
musculature remains associated with the cuticle through this treatment 
without gross structural alterations while nuclei and other 
cytoplasmic constituents are washed away.  Of the antisera prepared so 
far, the most interesting is a rabbit antibody to a 107,000 MW protein 
which by indirect immunofluorescence stains the dense-bodies of the 
bodywall musculature [the dense bodies serve as thin filament anchors 
analogous to the z-disc of vertebrate skeletal muscle].  As this 
protein cross-reacts with an antibody to smooth muscle alpha-actinin (
a component of smooth muscle dense-bodies) on nitrocellulose replicas 
of SDS-gels we presume it to be an alpha-actinin-like protein and are 
doing further experiments to test homology.  Antibodies to other 
purified polypeptides appear to recognize intermediate filaments or 
hypodermal cell structures limited to areas beneath the bodywall 
musculature that may be responsible for transmitting muscle tension to 
the cuticle.  Finally, an antibody to a 230,000 MW polypeptide lights 
up the nervous system circuitry: nerve ring, head neurons, dorsal and 
ventral cords, commisures, etc.  Although this antigen is 
uncharacterized, it could be the macromolecule recognized by peanut 
agglutinin which, by lectin fluorescence, is present in the broken and 
washed cuticles.  Currently mutants are being screened with these 
antibodies by immunofluorescence and two-dimensional electrophoresis 
but as yet we have no gene-protein correlations.