SARS-Coronavirus Replication Is Supported by a Reticulovesicular Network of Modified Endoplasmic Reticulum (original) (raw)
Figure 7
Detection of dsRNA in SARS-CoV–Infected Cells
SARS-CoV–infected Vero E6 cells were fixed at various time points after infection and processed for IF assays using rabbit antisera recognizing different replicase subunits and a mouse monoclonal antibody specific for dsRNA. Imaging was done using a confocal laser scanning microscope.
(A) Time-course experiment showing the development of dsRNA signal, which could be detected as early as 2 h p.i. Later in infection, the initially punctate cytoplasmic staining developed into a number of densely labeled areas close to the nucleus.
(B) Dual-labeling IF assays using antisera recognizing dsRNA and either nsp3 or nsp8. The early signals for dsRNA and both nsps (here shown at 3 h p.i.) were found in close proximity of each other and partially overlapped.
(C) High-resolution images of dual-labeling experiments for nsp3 and dsRNA early in infection (4 h p.i.), with the enlarged merged image illustrating that these signals were largely separated.
(D) See (C), but now a dual-labeling experiment for nsp8 and dsRNA was performed.
(E) High-resolution images of dual-labeling experiments for nsp3, nsp8, and dsRNA later in infection (6 h p.i.). Whereas the two nsps colocalized to a large extent (bottom row), this was less obvious when the labeling for dsRNA and replicase subunits was compared.
Scale bars represent 10 μm (A), 25 μm (B), or 5 μm (C–E).