Figure 3. Characterization of the NCX transporter
ncx-2 and the CCX transporter
ncx-8. (A) Predicted gene structure of the
ncx-2 splice forms on chromosome V. The amino acid position of the
gk879849 lesion is shown. The lesion in
gk879849 is defined by a premature opal stop codon at amino acid 634. (B) Bar chart of the percentage of expulsions per DMP cycle from 20 animals for wild-type animals,
ncx-2(
gk879849) mutant animals, and wildtype animals that were cultivated on bacteria expressing dsRNA targeting the
ncx-2 locus [
ncx-2(RNAi)]. In the case of the
ncx-2 mutants, there is a significant defect in the number of expulsions per cycle when compared with wild-type animals at P , 0.005 for
ncx-2(
gk879849) mutant animals and
ncx-2(RNAi) animals. (C) Bar chart of the average rate of egg laying per hour for wild-type,
ncx-2(
gk879849), and wild-type animals that were cultivated on bacteria expressing dsRNA targeting the
ncx-2 locus [
ncx-2(RNAi)]. Error bars represent the S.E.M; P , 0.05. For each genotype a sample size of 10 animals was obtained and the mean was calculated. (D) Representative plots of the velocity (mm/sec) for wild-type and
ncx-2(
gk879849) mutant animals when off food. The animals were transferred to an unseeded plate and allowed to roam for 10 min and then movies of movement were taken. (E) Bar chart of the average velocity for wild-type and
ncx-2(
gk879849) mutant animals when off food. Error bars represent the S.E.M. P-values were calculated using the Student's t-test. (F) Predicted gene structure of the
ncx-8 gene on chromosome V. The amino acid position of the lesion is highlighted for
ncx-8 (
gk234217), and the lesion in
gk324217 is defined by a premature stop codon at amino acid 513. (G) Expression of the
ncx-8 gene during the embryonic late morphogenesis stage. Bright-field image of an embryo (left) and GFP image of the same embryo (right). (H) Oil-Red-O staining in the intestine of a wild-type animal (top) and
ncx-8(
gk324217) mutant animal (bottom). The
ncx-8(
gk324217) mutant exhibits less Oil-Red-O staining. Oil- Red-O is used as a read-out for lipid accumulation in C. elegans (O'Rourke et al. 2009). Bar, 100 mm. (I) Quantification of Oil-Red-O staining in wild-type,
ncx-8(
gk234217) mutant animals, wild-type animals that were fed an empty control vector (L4440), and wild-type animals that were fed bacteria expressing dsRNA targeting the
ncx-8 locus. In the case of the
ncx-8(
gk234217) mutants and the animals that were fed RNAi clones targeting the
ncx-8 locus, the average Oil-Red-O staining is significantly lower when compared to wild-type animals or wild-type animals that were fed the control RNAi vector. P-values were calculated using the Student's t-test. Error bars represent the S.E.M.; P , 0.05. (J) Longevity assays of
ncx-8(
gk234217) mutant animals and wild-type animals at 20C (left), and longevity assays of wild-type animals cultivated on control RNAi plates and RNAi plates targeting the
ncx-8 locus (right). In each case a significant difference in survival was observed as compared with controls: P , 0.005 for
ncx-8 mutants vs. wild-type animals at 20C, and P , 0.005 for wild-type animals cultivated on control RNAi plates compared with wild-type animals cultivated on
ncx-8 RNAi plates at 20C. The P-values were calculated from log-rank tests.