Dynamin PRD and PH domains are required for the fusion of OCPs. (A) TRAP staining of transduced Dnm-DKO osteoclasts reexpressing vector, dynamin 1 (Dnm1), dynamin 2 (Dnm2) WT, and Dnm2 mutants including a GTPase mutant K44A, a PH domain mutant K562E, and a splice variant ΔPRD. Bars, 200 µm. (B) Quantification of TRAP-positive cells with more than three nuclei for fusion rescue efficiency. One-way ANOVA (P < 0.001) and a Student’s t test were used to analyze the data. a, significantly different from vector (P < 0.001); b, significantly different from Dnm2 (P < 0.034).