Figure 31.

Identification of HIV-1 fusion sites by single-virus imaging. (a) Schematic presentation of redistribution of viral lipid and content markers upon fusion with a plasma membrane (left) and with an endosome (right). Viruses colabeled with membrane (red) and content (green) markers are pseudocolored yellow. (b and c) Partial fusion of JRFL with the plasma membrane of TZM-bl cells. The time from the beginning of imaging is shown. The two-dimensional projection of the particle’s trajectory (cyan) is overlaid on the last image. Changes in fluorescence intensities (in arbitrary units) of membrane (red) and content (green) markers, as well as the instantaneous velocity (blue trace) of the particle, are shown. Adapted with permission from ref (83). Copyright 2009 Elsevier.