Cdc42GAP regulates HSP F-actin assembly, adhesion, and migration. (A) WT or homozygous LSK E14.5 fetal liver cells were isolated by FACS and cultured overnight in the chamber slides. Cells were stimulated with 100 ng/mL SCF or 100 ng/mL SDF-1α for 10 minutes and stained for F-actin with TRITC-conjugated phalloidin. (B-C) WT or homozygous low-density fetal liver (n = 10 for each group) cells were subjected to adhesion and migration assays in vitro. The percentages of the cells that adhered to an H-296 fragment of fibronectin after 1-hour incubation (B) and that migrated toward a 100 ng/mL SDF-1α gradient in 4 hours in a Transwell migration chamber (C) were calculated based on the colony-forming activities of the total input cells and the adherent or migrated cells assayed in a methylcellulose medium containing 100 ng/mL SCF, 100 ng/mL IL-3, 4 U/mL EPO, and 100 ng/mL G-CSF.