Chlamydomonas ARL3 is dispensable for ciliation and IFT. (A) arl3-282 is an ARL3-null mutant. Immunoblots with the affinity-purified ARL3 antiserum identified ARL3 protein with a size of ∼20 kD in whole cell (WC) samples of CC-5325 but not arl3-282 cells. MW stands for molecular weight. (B)arl3-282 cells assemble cilia with normal length. Representative phase contrast images of CC-5325 and arl3-282 cells were shown (left). The number of cells which have cilia in 20 counted cells was listed for each strain. Inset magnification (100 times) was shown. Scale bar: 10 µm. arl3-282 cells had full-length cilia (10.47 ± 0.82 µm, n = 20) compared to CC-5325 cells (10.57 ± 0.76 µm, n = 20). Mean lengths are listed; error bar indicates SD, and n indicates the number of cilia counted and listed in each bar. ns: non-significance (right). One sample unpaired Student’s t test is indicated. (C) Immunoblots of WC samples of three group cells including CC-125, ARL3; IFT43:HA:YFP-TG, and arl3-282; IFT43:HA:YFP-TG (left); CC-125, ARL3; IFT22:HA:YFP-TG, and arl3-282; IFT22:HA:YFP-TG (middle); and CC-125, ARL3; IFT38:YFP-TG, and arl3-282; IFT38:YFP-TG (right) probed with α-IFT43, α-IFT22, and α-IFT38, respectively. For each group of the cells, the YFP- or HA-YFP-tagged proteins of both CC-125 and arl3-282 background were determined to express at the WT CC-125 protein levels. (D) Immunoblots of WC samples of CC-5325, arl3-282, and arl3-282; ARL3:HA:YFP-TG probed with α-ARL3. For A, C, and D, α-tubulin we used as a loading control. Source data are available for this figure: SourceData FS3.