Worm Breeder's Gazette 3(1): 14

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.

R73 - A Correction

R.H. Waterston

The strain R73 has previously been described as a revertant of unc-
54(e569) (Epstein, et al., J.  Mol.  Biol.  (1974) 90:291-300; 
Mackenzie and Epstein, Nematode workshop, 1977).  However, the fine 
structure as described by Mackenzie in Woods Hole strongly resembled 
the muscle of putative missense alleles of unc-15 (Waterston, et al., 
J.  Mol.  Biol.  in press) and not that of any of the other mutants so 
far isolated and examined (Waterston, unpublished).  Accordingly, R73 
was obtained from H.  Epstein and further genetic studies carried out.
R73 fails to complement unc-15(e1214), with R73/e1214 heterozygotes 
resembling R73 in their muscle structure by polarizing microscopy.  
This defect in muscle structure maps close to dpy-5 I, and three 
factor crosses indicate that the mutation(s) lies near or to the right 
of unc-13.  No evidence for a mutation(s) in the unc-54 gene was found.
Thus R73 is apparently a partial revertant of an unc-15 allele, 
probably e73 and not unc-54(e569) (Where the error in bookkeeping 
occurred is unclear), and the large paracrystalline arrays, presumably 
of paramyosin, remain characteristic only of presumptive missense 
alleles of unc-15.