Fig. 6. Src catalytic activity affects podosome development. Osteoclasts derived from RAW cells expressing GFP-actin (control) or co-expressing GFP-actin and SrcY527F (SrcY527F), or GFP-actin and Src251 (Src251), were fixed and double-stained (A) for vinculin and actin, or (B) for Src pY418 and actin. (A) The vinculin/actin ratio indicates a typical double ring structure in control cells. Notice the poorly organized SZL structure in the SrcY527F cell and podosomes with incomplete ring domains, organized in clusters, in the Src251-expressing cells. (B) High levels of Src pY418 (src418) in the inner belt surround control and SrcY527F cells, and surround podosomes in Src251 cells. Bars, 10 µm.