Figure 4.
Functional interactions between TZ proteins are required for correct cilium length and positioning of basal bodies/TZs, as well as chemosensation. (A and B) Disruption of mks-5 (A) or mks-6 (B) has no major effect on the gross morphology/presence of amphid (head) and phasmid (tail) cilia, as revealed by GFP-tagged IFT markers (OSM-6 and CHE-2, respectively). BB, basal body. Bars, 5 µm. (C) Analyses of amphid and phasmid cilia length (white and light gray bars), spatial distribution of BB/TZ in amphid channel neurons (black bars), and position of the BB with respect to the cell body in tail neurons (dark gray bars) are summarized based on phenotypes and statistical analyses shown in Fig. 5. Mean values obtained for wild-type (N2) are shown; *, statistically significant difference (P < 0.01) vs. N2; §, statistically significant variance (P < 0.01) vs. N2. Schematics illustrate how measurements were made for amphid and phasmid cilia lengths, the distribution of BBs within amphid neurons (some BBs in mutants do not form a tight cluster as in wild type), and distance of the cilia from the phasmid neuron cell body (some mutants have abnormally short dendrites, indicating lack of anchoring of upon retrograde extension of the cell body during development). (D) Graph of cilium-dependent osmotic avoidance of N2 and TZ mutant strains. osm-5 (control IFT mutant) fails to avoid high osmolarity solution. Two mks-6 alleles show osmosensation defects in an nphp-4 mutant background, as do mksr-2 and mks-5 mutants. *, significant difference compared with N2 (P < 0.05); **, significant difference compared with either single mutant for the indicated double mutant.