At 12 h post-transfection, cells were also infected with BTV-1 (m.o.i. = 1) for 1 h at 37uC. The cells were then washed to remove excess virus and infection continued for a further 11 h when the cells were fixed and processed for confocal microscopy. Infected cells were identified using a rabbit antibody (Orab1) as described above. The frequency of infection of the cells expressing DNdynamin-2 was normalised to the level of infection of the cells expressing the wt protein. Figure 4I shows that expression of DNdynamin-2 does not inhibit BTV-1 infection. These results are consistent with those obtained using DN-Esp15 and AP180C and support our conclusion that BTV-1 can enter BHK cells using a clathrin-independent pathway. Furthermore, as the 'aa' splice variant of DN-dynamin-2 also inhibits caveolae-mediated endocytosis, the above results also support our conclusion that caveolae are unlikely to be required for virus entry and infection.