PLD fails to move by IFT carriers in arl13 cilia. (A) Western blot of isolated cilia from control (g1, WT) and arl13 probed with antibodies against BBS1, BBS3, BBS4, BBS5, and IC2, as a loading control. The quantification of the band intensities normalized for those of IC2 is shown in brackets and is based on one experiment. (B) Western blot of isolated cilia from WT, bbs4-1, arl13, bbs4-1 BBS4-GFP, and arl13 bbs4-1 BBS4-GFP strains probed with antibodies against GFP, BBS4, ARL13, PLD, and IC2 as a loading control. The quantification of the anti-ARL13 band strengths normalized for those of IC2 are shown in brackets and is based on one experiment. Note that ARL13 remained elevated in cilia of the bbs4-1 BBS4-GFP strain. (C) TIRF images and corresponding kymograms of bbs4-1 BBS4-GFP and arl13 bbs4-1 BBS4-GFP cilia. The ciliary tips (T) and bases (B) are indicated. Bars = 2 µm and 2 s. (D) Violin plot of the anterograde and retrograde IFT frequencies of BBS4-GFP in bbs4-1 BBS4-GFP and arl13 bbs4-1 BBS4-GFP cilia. The number of cilia analyzed and the P values of a two-tailed t test are indicated. (E) TIRF images and corresponding kymograms of PLD-NG in control (g1, WT), bbs4-1 and arl13 cilia. Note anterograde (arrowheads) and retrograde (arrow) IFT of PLD-NG in control cilia. The ciliary tips (T) and bases (B) are indicated. Bars = 2 µm and 2 s. Source data are available for this figure: SourceData F3.