C. elegans
srf-6 mutants were isolated using altered surface immunofluorescence as phenotype (Hemmer et al., 1991; Grenache et al., 1996). In Van Sciver et al., 2019, we showed by whole genome sequencing that three different
srf-6mutants carry mutations in gene
nsy-1.Well-characterized mutant alleles of
nsy-1result in hermaphrodites that express the olfactory receptor gene
str-2 in both AWC neurons (2AWCON, Troemel et al., 1999), unlike wild type hermaphrodites, which express
str-2 asymmetrically in only one of the two AWC neurons (1AWCON, Troemel et al., 1999). Our sequencing results suggested that
srf-6mutants might have a similar 2AWCONphenotype. We therefore examined
srf-6(
yj13)for its AWC phenotype.
In order to introduce an
str-2::GFPmarker into the
srf-6 genotype, firstsrf-6
(yj13)
unc-4(
e120) II and
nsy-1(
ok593)
unc-4(
e120) II double mutants were constructed as described (Hemmer et al., 1991). Homozygous males carrying the construct kyIs140, which contains an
str-2::GFP fusion integrated on chromosome I (Troemel et al., 1999), were mated with
srf-6(
yj13)
unc-4(
e120) II hermaphrodites, and an Unc F2 hermaphrodite expressing GFP in chemosensory neuron AWC was cloned. An individual hermaphrodite descendant, all of whose offspring expressed GFP, was isolated to establish a strain of genotype kyls140 I;
srf-6(
yj13)
unc-4(
e120) II. A strain of genotypekyls140 I;
nsy-1(
ok593)
unc-4(
e120) was constructed similarly. Adult hermaphrodites from these strains were examined in a fluorescent microscope for their AWC phenotype. Figure 1 shows thatsrf-6
(yj13) adults exhibited a 2AWCON phenotype similar to that of
nsy-1(
ok593).
To test whether
srf-6(
yj13) andnsy-1
(ok593) affect the same or different genetic functions, a complementation test was performed (Figure 1, last two lines). Males of genotype
srf-6(
yj13) were mated with kyls140 I;
nsy-1(
ok593)
unc-4(
e120) II hermaphrodites, and non-Unc offspring were scored in a fluorescent microscope for the AWC phenotype. The complementation heterozygotes showed a 2AWCONphenotype similar to that of
nsy-1(
ok593). This result included data from two separate crosses. In contrast, when wild type males were mated with kyls140 I;
nsy-1(
ok593)
unc-4(
e120) II hermaphrodites, the 1AWCONphenotype was observed. These results included worms from one cross.
These results indicate that
srf-6(
yj13) andnsy-1
(ok593) mutations do not complement each other for the 2AWCONphenotype, and together with the
srf-6 mutant sequencing results (Van Sciver et al., 2019), we conclude that
srf-6and nsy-1 are the same gene.