BEET WESTERN YELLOWS LUTEOVIRUS CAPSID PROTEINS PRODUCED BY RECOMBINANT BACULOVIRUSES ASSEMBLE INTO VIRION-LIKE PARTICLES IN CELLS AND LARVAE OF BOMBYX-MORI

We subcloned various constructs of the beet western yellows luteovirus (BWYV) 3' proximal genes into Bombyx mori nuclear polyhedrosis virus (BmNPV) transfer vectors and constructed recombinant BmNPVs. The recom binant BmNPVs were used to infect BmN cells and B. mori larvae. Protei n expression was analyzed by SDS-PAGE and immunoblot analysis, and the BWYV-encoded capsid protein (CP), P19, readthrough protein (RT), and a modified capsid-readthrough protein (CP-RT) were detected in BmN ce lls infected by the respective BmNPVs. However, we detected only the B WYV CP and P19 in BmN cells infected with a recombinant BmNPV containi ng all three BWYV 3' proximal genes. BmN cells and fat body cells from B. mori larvae infected with recombinant BmNPVs were analyzed by tran smission electron microscopy and immunogold labeling. Particles which morphologically and serologically resembled BWYV virions were detected in the nuclei of BmN cells and B. mori larval fat body cells infected with recombinant BmNPVs producing either the BWYV CP alone or BWYV CP plus a BWYV CP-RT. Similar particles were not detected in cells infe cted with a control BmNPV or recombinant BmNPV producing only CP-RT. (C) 1995 Academic Press, Inc.