Figure 1

BTV induces aberrant mitosis in cultured mammalian cells. Cells were cultured in the presence of growth medium containing 10% serum and either infected or mock infected with BTV. At 16–24 hours post infection cells were fixed with paraformaldehyde and prepared for confocal immunofluorescence microscopy as described in the Materials and Methods. (A) Uninfected BHK-21 cells showed highly organised and symmetrical microtubule spindles. (B) In contrast, BTV-16v infected mitotic cells had multiple, disorganised and asymmetric spindles (alpha tubulin labelling in green) that were disassociated from the condensed chromosomes (blue). (C) and (D) BTV-1 and BTV-8 were also able to induce aberrant mitosis in BHK-21 cells, with NS2 (red) associated with the chromosomes. Vero cells and bovine pulmonary aortic endothelial (BPAEC) cells infected with BTV-16v (F) and (H) also showed abnormal mitotic events compared to the uninfected controls (E) and (G). Scale bar = 10 μm.