FIGURE 3:

Expression of IFT46_106-344 partially rescues the ift46-1 phenotype. Cells of ift46-1 were cotransformed with a gene that expresses IFT46_106-344 and, on a separate plasmid, a drug-resistance gene that served as a selectable marker. Among the resulting transformants, ∼10% were partially rescued; they mimicked the Sup_ift461 phenotype in that some cells could assemble longer flagella and swim slowly when stressed by growing in 96-well plates. The panel shows a Western blot of cell lysates from the motile transformants and wild-type, ift46-1, and Sup_ift461 cells probed with the anti-IFT46C antibody; all of the partially suppressed strains expressed the truncated IFT46 protein, albeit at different levels. Strain YH6RT4 was chosen for further analysis and renamed ift46-1 IFT46Δ105. A blot of the same samples diluted 1:20 was probed with an anti-tubulin antibody as a loading control. Supplemental Figure S1 provides evidence that the motile transformants resulted from independent transformation events. In a control experiment, 200 cell lines obtained by transformation with the drug-resistance gene alone were examined and all found to be nonmotile.