Fig. 3. The endogenous Inv protein is also localized to primary cilia. (A) Primary fibroblasts established from wild-type (+/+), Inv/+, Inv/Inv, Inv/Inv, Inv::GFP mice were subjected to western blot with an anti-Inv antibody. The endogenous Inv protein (asterisk) is detected in +/+ and Inv/+ fibroblasts but not in Inv/Inv fibroblasts. The antibody also detected the Inv::GFP protein (arrowhead) in Inv/Inv, Inv::GFP fibroblasts. (B) Primary fibroblasts derived from Inv/Inv, +/+ or Inv/Inv, Inv::GFP mice were subjected to double staining with anti-acetylated tubulin (a-c, green) and anti-Inv antibody (d-f, red). Note that primary cilia are positive for acetylated tubulin (a-c, arrowheads). The anti-Inv antibody detects primary cilia in +/+ (e) and Inv/Inv, Inv::GFP (f) fibroblasts, but not those in Inv/Inv fibroblasts (d).