Worm Breeder's Gazette 9(2): 83
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.
Thin filament assembly of C. elegans muscle is severely disorganized in strains homozygous for the unc-60 mutation (Waterston et al. 1980). unc-60 is located near the left end of LGV, a region of interest to our lab. We have undertaken a fine structure analysis of unc-60 mutations. Available for study were the alleles e677, e890, e723 (Brenner 1974), m35 (D. Riddle) and r398. All are paralyzed except r398 which moves well as an adult but exhibits a paralyzed phenotype when linked to unc- 34. This allele was isolated as a unc-105 suppressor by P. Anderson. Three new alleles were induced in this lab in an F1 screen utilizing a let-x(s704) 310) eT1 balancer chromosome (see McKim et al. this issue). The induction frequency of unc-60 alleles was 1/4000 using 0.012M EMS. Heterozygotes of the genotype unc-34(e556) +/+ unc-60(y) 24) were selfed and the F2's screened for mobile animals. The map shown in Figure 1 has been constructed. Points to note are: 1) The recombinational size (0.01-0.017 mu.) of unc-60 is larger than unc-15 or unc-13 and equivalent to unc-22 and unc-54. unc-54 makes a better comparison because like unc-60, it is found outside a gene cluster. 2) Except for r398, all 6 mapped alleles are clustered at two points. This may reflect a limited number of sites available for mutational alteration to the severely paralyzed phenotype. s1307 has not been mapped because like r398, it is a weak allele. e677 and e890 are lethal over sDf28. We thus consider unc-60 as an essential gene. For example it may have function in the pharyngeal musculature. sup-7 (Waterston 1981) does not suppress e677, e890, e723 or m35. The rest are being tested. All alleles are hypomorphs by deficiency tests. [See Figure 1]