Fig. 2
From: Cilia regeneration requires an RNA splicing factor from the ciliary base
Auxin-induced degradation of PRP-8. A Schematic model of the auxin-induced degradation system in the presence of 4 mM auxin. Transgenic E3 ubiquitin ligase TIR1 can bind degron-tagged PRP-8 and label this protein with ubiquitin (Ub) chains. Polyubiquitinated PRP-8 is degraded by the proteasome. Degron-tagged PRP-8 in other tissues remains stable because transgenic TIR1 (single copy) is expressed under the control of the ciliated neuron-specific Pdyf-1 promotor. B PRP-8 at the ciliary base is degraded in the presence of 4 mM auxin. Defective cilia (e.g. without distal segments) can be seen when visualized with a DYF-11::wrmScarlet marker. m.s., middle segment; d.s., distal segment. C Localization of PRP-8 in the presence of 4 mM auxin. The positions of amphid (D) or phasmid (E) nuclei are indicated in gray boxes. Phasmid cilia are indicated in yellow (F) or gray (G) box. Scale bar, 10 μm. D Enlarged amphid nuclei indicated in (C). E Enlarged phasmid nuclei indicated in (C). Nuclei are indicated by white arrows. F Enlarged phasmid cilia indicated in yellow box in (C). Ciliary bases are indicated by yellow arrows. G Enlarged phasmid cilia indicated in gray box in (C). Ciliary bases are indicated by white arrows. H-M Representative images of defective phasmid cilia in the presence of 4 mM auxin. Ciliary tips are indicated by yellow arrows. Scale bar, 2 μm. N Percentage of abnormal cilia in the two groups. IAA (+) group was treated with 4 mM auxin on NGM plates for 24 hours. IAA (−) group was not treated with auxin on NGM plates for 24 hours. For each worm, two cilia from different phasmids are counted. n indicates the number of cilia. **P < 0.01 via Fisher’s exact test. O Quantification of nuclear PRP-8 intensity in IAA (+) group. Normal or abnormal cilia correspond to those in (N). The mean intensity of normal group is normalized to 100%. n indicates the number of nuclei. P Quantification of ciliary basal PRP-8 intensity in IAA (+) group. Normal or abnormal cilia correspond to those in (N). The mean intensity of normal group is normalized to 100%. n indicates the number of cilia. **P < 0.01 and ****P < 0.0001 and ns denotes P > 0.05 via unpaired t-test. Error bars, SD. Q-R Scatterplot of each cilium in IAA (+) group. The length of cilia with their nuclear PRP-8 intensities are plotted in (Q). The length of cilia with their ciliary basal PRP-8 intensities are plotted in (R). r indicates the Pearson correlation coefficient. ****P < 0.0001 and ns denotes P > 0.05 via paired t-test