Fig. 2. CAM-1 CRD binds Wnts CWN-1, EGL-20 and MOM-2. Drosophila S2 cells expressing Neurotactin (Nrt)-HA-tagged C. elegans Wnts were incubated with secreted CRDs of C. elegans Wnt receptors fused to alkaline phosphatase (CRD-AP). (A) Levels of Nrt-HA-Wnt fusion proteins (130 kD) expressed by S2 cells were measured by anti-HA immunoblot. Wnts are post-translationally modified and this might account for the detection of multiple bands. Anti-GAPDH provided a loading control. (B) Amount of CAM-1 CRD-AP retained by Nrt-HA-Wnt-expressing S2 cells. The assay was performed in triplicate. As the untransfected sample appeared to contain slightly fewer cells, we used cells expressing Nrt-CWN-2 (which expressed Wnt, but did not bind CAM-1 CRD-AP) as a negative control for statistical analysis. ^*, P<0.05, calculated using Fisher's exact test. Error bars, s.e.m.