TEM analysis of the DMVs in HEK-293T cells, confocal microscopy analysis of dsRNA signal in the SARS-CoV-2–infected Vero-E6 cells and MHV-A59–infected 17Cl-1 cells, and the expression level of NSP3/4 only affects the density but not the size of DMVs, related to Fig. 5 . (A) The schematic structure of the SARS-CoV-2 genome template. (B) TEM analysis of the DMVs induced by SARS-CoV-2 NSP3/4 (left), NSP3-16 (middle), and NSP3-16+dsRNA (right) in HEK-293T cells. Each boxed area in a low-magnification TEM micrograph (upper) is depicted in detail in a high-magnification one (bottom). Scale bar, 2 μm for low-magnification TEM micrographs, 200 nm for high-magnification TEM micrographs. (C and D) Confocal microscopy analysis of dsRNA signal in the SARS-CoV-2–infected Vero-E6 cells at 6 or 24 hpi (C) and MHV-A59–infected 17Cl-1 cells at 4 or 8 hpi (D) with or without RDV treatment. Scale bar, 20 μm. (E) IB analysis of the NSP3 and NSP4 expression in Vero-E6 cells in SARS-CoV-2 infected at 6 or 24 hpi with or without RDV treatment. n = 3 independent experiments. (F) IB analysis of the NSP3 and NSP4 expression in low-dose (2 μg) and high-dose (4 μg) NSP3/4 transfection. n = 3 independent experiments. (G) TEM analysis of the DMVs induced by low-dose (2 μg, left) and high-dose (4 μg, right) NSP3/4. Scale bar, 200 nm. (H) Quantification of the size of DMVs is shown as mean ± SEM. n (number of analyzed DMVs) = 52 and 72; quantification of DMV density is shown as mean ± SEM. Student’s two-tailed t test, *: P < 0.05. ns: not significant. Source data are available for this figure: SourceData FS4.