FIG. 7.
Ultrastructural observations of induced 293-BFRF1-KO cells and 293-BFRF1-KO cells complemented with BFRF1. Left and center micrographs: numerous nucleocapsids are present in the nuclei of induced BFRF1-KO cells and are distributed mainly in the proximity of the nuclear membrane (arrows). Insets show an higher magnification of fully assembled intranuclear nucleocapsids containing electron-dense material corresponding to viral DNA. Right micrograph: few nucleocapsids (arrows) are visible in BFRF1-complemented cells. A typical multilayered reduplication of the nuclear membrane (NM) is shown. An extracellular mature virion is shown at higher magnification in the inset. PM, plasma membrane; Nu, nucleus. Bars, 1 μm (0.1 μm in the insets).