Worm Breeder's Gazette 9(2): 83

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Fine Structure Analysis of unc-60V

K.S. McKim, L.M. Turner, and D.L. Baillie

Figure 1

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]

Figure 1