Targeting strategy to inactivate gcsfrgene.

(A) Targeting strategy to delete exons 7 to 16 of the gcsfrgene in ES cells. The position of the probe used to screen recombinant colonies is shown. Southern analysis of HindIII digests of gDNA detected a 9.6-kb band from the WT allele and a 7-kb band from the targeted allele (not shown). pBKS indicates pBluescript KS (Stratagene, La Jolla, CA). (B) Specific binding of G-CSF to bone marrow cells from gcsfr^+/+,gcsfr^+/−, and gcsf^-−/−mice analyzed by flow cytometry. Cells were incubated with biotinylated G-CSF in the absence (solid line) or presence (dotted line) of a 100-fold molar excess of nonlabeled G-CSF followed by incubation with PE-conjugated streptavidin.