A model depicting early stages of PBCV-1 infection and highlighting the similarity between PBCV-1 infection and that of bacteriophages.

<p>A. The main components involved in PBCV-1 infection, including the PBCV-1 icosahedral capsid (yellow), internal membrane (dark blue), genome (gray) and spike (magenta) on the left side of the panel, as well as the cell wall (brown), cellular membrane (dark blue), thylakoid stacks (green), nuclear membrane (light blue) and nucleus (gray) of the host on the right side. B-D. Spike-mediated perforation of the host cell wall, protrusions of the viral and cellular internal membranes and their subsequent fusion into a membrane tunnel. D, E. Internalization of PBCV-1 genome into the host cytoplasm through a membrane tunnel, accompanied by the perforation of the photosynthetic thylakoid stacks and apparently promoted by viral DNA condensation. Significantly, perforation of the host cell wall, generation of a membrane portal and genome condensation represent crucial infection stages of bacteriophages (see text for details).