Actin polymerization is required for DNase activity in podosomes. (a) RAW264.7 cells were plated on SNS surfaces with actin polymerization inhibited by cytochalasin D or myosin II inhibited by blebbistatin. (b) The bar graph showed that the cytochalasin D significantly reduced the DNase activity in podosomes, whereas blebbistatin had a minor effect on DNase activity. 100 podosomes were analyzed for each data point. The significance (P value) was evaluated by two-tailed tests. Error bars represent SD.