Model of gain of CDC42 activity. C57BL/6 cells mice reconstituted with WT or CDC42GAP^–/– embryonic day (E)–14.5 fetal liver cells. The reconstituted animals were used 5 weeks after bone marrow reconstitution. (A) CDC42, Rac, and RhoA activities of bone marrow–derived neutrophils. Rho GTPase activity was assessed by the standard pull-down assay using the PAK-binding domain for CDC42 and Rac or the Rhotekin-binding domain for RhoA. The histogram represents the relative ratio of GTP-Rho GTPase versus total protein. β-actin was used as loading control. (B) Neutrophil recruitment into peritoneal cavities after challenge with 3% thioglycollate. Peritoneal lavages were performed 4 and 18 hours after challenge, and total cells were enumerated with a hemocytometer. Neutrophil content was evaluated after cytospin preparation of the cells and Diff Quick staining. Mean ± SEM from 3 independent experiments.