Worm Breeder's Gazette 8(1): 8
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.
We have isolated a variety of muscle defective mutants by reverting the paralyzed mutant unc-105(n490). n490 is severely paralyzed, apparently due to hyper-contraction of body-wall muscle cells. Revertants having improved motility are easily visualized among their paralyzed siblings. Wild-type revertants have been described by Joan Park (see Newsletter 7:49) as null alleles of unc-105. We find that partial revertants of n490 are often muscle defective. Being muscle defective, such mutants are unable to generate the force required for the n490 mutant phenotype. Thus, they are isolated as suppressors of hyper-contraction. Although these revertant strains have an uncoordinated phenotype, they are usually more motile than n490, and this serves as the basis for their selection. We used this reversion to isolate spontaneous unc-54 and unc-22 mutations (see 1983 Meeting Abstracts), and have now begun to analyze other classes of n490 revertants. We hope that among these revertants will be novel muscle defective mutants. We mutagenized cultures of n490 and picked partial revertants among the F2 progeny. As expected, many Twitcher revertants (presumably unc- 22) were observed; we have not analyzed this class. The remaining partial revertants were screened for abnormal muscle using polarized light microscopy. We are in the process of analyzing 117 partial revertants of n4900 74 of these revertants are muscle defective. Thus far, we have identified twenty additional alleles of unc-54 and one allele each of unc-52, utations complement alleles of all the known genes having a similar muscle defective mutant phenotype. These mutations may define new muscle genes. Interestingly, another 21 of the muscle defective revertants appear to contain dominant Unc's that have a recessive lethal phenotype. Several of these mutations have been segregated away from n490; they are muscle defective as heterozygotes and are inviable as homozygotes. Finally, two additional alleles of unc-15 have been identified among our collection of spontaneous revertants. We hope that these revertants will define new loci involved in development and function of the body-wall muscle and provide additional alleles of the already identified genes.