Expression of plant virus silencing suppressor genes in Drosophila cells. A. Immunoblot of lysates from control cells (lanes 1,2 and 5,6), cells transiently transfected with pMT-2b (lanes 3,4) or cells stably transformed with pMT-2b (lanes 7,8). Cells represented in lanes 2, 4, 6 and 8 were induced by addition of CuSO4 and cells represented in lanes 1, 3, 5 and 7 were uninduced. Lanes 9 and 10 were lysates from control plant or plant infected with CMV respectively. Lysates were analysed by polyacrylamide gel electrophoresis, proteins transferred to nitrocellulose by electroblotting and probed with an anti-2b antibody. The position of migration of a SeeBlue Plus 2 Pre-stained molecular weight marker (Invitrogen) band is shown. B. Northern blot analysis of RNA from control cells (lane 1) or cells transfected with pMT-HC-Pro (lane 2) or with pMT-HC-Pro/K (lane 3). Total cell RNA was separated on 1% agarose gels, transferred to nylon membrane and probed with an HC-Pro specific probe. The position of migration of a digoxigenin-labeled RNA molecular weight marker (Roche Molecular Biochemicals) band is shown. C. Northern blot analysis of RNA from DS2-HC-Pro cells (lane 1) or control cells (lane 2). RNA was examined as above. The position of migration of a digoxigenin-labeled RNA molecular weight marker band is shown.