Fig. 3. Phenotype of Dictyostelium phlp1^– and phlp3^– disruptants. The genes were inactivated by homologous recombination. (A) Phenotype of wild-type AX3, phlp1^–, phlp1^–/phlp1^OE and phlp3^– cells on non-nutrient agar plates. Photographs were taken after 30 h of starvation. (B) Dose–response curves of chemotaxis towards cAMP and folic acid. The response to a range of cAMP concentrations was measured in droplets using the small- population assay. An agar cutting assay was used to score for chemotaxis to different concentrations of folic acid: AX3 (open circles), phlp1^– (closed circles), phlp1^–/phlp1^OE (squares) and phlp3^– (triangles).