PBCV-1 genomes detected in host chloroplasts, presumably on a direct track to the host nucleus.

A, B. Cells infected with PBCV-1 for 6 min and thin sections were subjected to In Situ hybridization. A. Low magnification view of a cell showing viral DNA inside chloroplasts. B. High magnification view of inset in panel A. Viral DNA is marked by the inset. Viral DNA is located at membrane stacks on a trajectory to the nucleus. C, D. TEM sections of PBCV-1 infected cells at 2 min PI. Empty capsids are detected near chloroplast stacks. Note the discontinuity of the chloroplast membrane stacks (red arrowhead) at the point of DNA ejection. E, F. Thin section of a 2 min PI chlorella-infected cell. E. Low magnification view of a chlorella cell with a virus near the chloroplast in the process of DNA ejection. F. High magnification view of the inset in panel E. Note the discontinuity of the thylakoid membrane stacks (red arrowheads).Nu: nucleus, Ch: chloroplast. Scale bars: A,E: 500 nm; B,F: 100 nm; C, D: 200 nm.