Genomic retention of both WASP and SCAR correctly predicts pseudopod formation by the infectious chytrid fungus Bd. (A) Time lapse showing examples of dynamic pseudopods from chytrid cells with (top) and without a flagellum (middle) or one cell of each (bottom). See also Video 3. (B) Percentage of cells with pseudopods within the first 6 h after release from zoosporangia. The mean and SD (bars) of four biological replicates (dots) is shown, with 3,782 cells total. (C) Pseudopod extension rates. The means and SD (bars) of the individual values (dots) combined from three biological replicates is shown. (D) Scanning electron micrographs of fixed chytrid zoospores. Brackets denote pseudopods and arrowheads denote flagella. See also Fig. S4 B for more examples.