Worm Breeder's Gazette 1(2): 23

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.

Multiple Myosins in Body Wall Muscle Cells

F. Schachat, H. Epstein

Purified native myosin (1) from the paralyzed mutant E675 has two 
heavy chains which can be resolved by sodium dodecyl sulfate 
polyacrylamide gel electrophoresis (2).  The ratio of the two chains 
remains constant within 10% during purification.  We have fractionated 
native myosin from this mutant by hydroxyapatite chromatography and 
have demonstrated the existence of homologous myosin molecules 
composed only of one kind of heavy chain.  Comparison on 8M urea-
sodium dodecyl sulfate polyacrylamide gels of cyanogen bromide cleaved 
fragments (3) from pooled fractions enriched for either homologous 
myosin reveals multiple differences in primary structure.  Similar 
peptide differences have been obtained with analogous chromatographic 
fractions from N2 myosin.  These results suggest that at least two 
structural genes code for myosin heavy chains.  Material from the 
center of the E675 chromatogram contains approximately equal 
quantities of both heavy chains and rebands true on hydroxyapatite, 
indicating the existence of a heterologous form of myosin.  If this 
represents a heterologous myosin, it would demonstrate that the two 
heavy chain types arise from the body wall muscle cells.  We are 
currently investigating this possibility.