Fig. 5. Distribution of paxillin, Pyk2, integrin Vß3 and cortactin in the podosome zones of chicken and human osteoclast-like cells. Confocal immunofluorescence images of cells double-stained with rhodamine phalloidin (red) and with antibodies for paxillin, Pyk2, Vß3 or cortactin (green in colored images or white in grayscale images) are shown. Right-hand panels are high-power views, which were also scanned in the z-axis at positions indicated by the double-arrows. These z-axis scans are shown on top of these panels with the extracellular substrate-facing cell side oriented towards the bottom of the images. Note the co-distribution of paxillin, Pyk2 and Vß3 around and between, but not within, the F-actin core structures of podosomes. By contrast, cortactin shows an inverse distribution, i.e. colocalization with F-actin in xy-scans, but appears also orientated towards the basal podosome side, as indicated by the separation of red (F-actin) and green (cortactin) channels in the inset scanned in the z-axis.