FIG 3.

BBSV replication occurs in ER membrane-associated spherules. (A and B) Immunogold labeling of the auxiliary replication protein p23 in BBSV-infected N. benthamiana cells. (A) p23 is localized to the ER. (B) p23 is localized to the aggregated ER or in close proximity to the spherules. The arrow indicates the ER. The arrowheads point to spherule-associated 10-nm gold particles. (C and D) Examples of immunogold labeling of dsRNA in membrane-associated spherules. The arrowheads indicate areas of spherules labeled with 10-nm gold particles. Note that the distance between the gold particles and the target epitopes may span up to 20 nm, as reported previously (44). CW, cell wall. Scale bar, 200 nm.