Fig. 8. Surface CSF1R expression and colocalization with RhoGAP is reduced in Bcl6^–/– macrophages. RhoGAP (C and D) colocalizes with the CSF1R (E and F) at the plasma membrane. Localization of RhoGAP and the CSF1R to the plasma membrane both appear reduced in Bcl6^–/– BMM. Up to 20-25% of BMM may be binucleate. Arrowheads highlight plasma membrane ruffles. (G) CSF1R western blot analysis showed reduced expression of the mature 165 kDa isoform in Bcl6^–/– BMM and the presence of a potential proteolytic cleavage product with molecular mass of 100 kDa. Lower panel, GAPDH loading control. (H) FACS analysis of surface CSF1R expression in vector-transduced Bcl6^+/+ and Bcl6^–/– BMM, and BCL6-reconstituted Bcl6^–/– BMM. Bar, 10 µm.