Architecture and biogenesis of plus-strand RNA virus replication factories

Figure 1 Classification and morphologies of plus-strand RNA virus-induced membrane alterations as revealed by electron tomography and three-dimensional reconstruction. Morphological similarities of membrane structures belonging to the invaginated vesicle (InV)/spherule type (A-C) or the DMV type (D-F). A: Flock-house virus (FHV); B: Rubella virus (RUBV); C: Dengue virus (DENV); D: Poliovirus (PV); E: Severe acute respiratory syndrome coronavirus (SARS-CoV); F: Hepatitis C virus (HCV). A: FHV-induced spherules (white) in the outer mitochondrial membrane (OMM; blue); B: InVs (white) and rigid membrane sheets (dark brown) in a modified endosome (the cytopathic vacuole, CPV) (yellow) in cells replicating RUBV. The rough endoplasmic reticulum (ER) is shown in light-green and mitochondria in red; C: Spherule-like invaginations (InVs) in the endoplasmic reticulum (ER) (brown) observed in DENV-infected cells. Newly formed progeny virions are shown in red; D: PV infection induces single membrane tubules (SMT) (blue), double membrane vesicles (DMVs) and multi membrane vesicles (MMVs). The DMV outer membrane is shown in green, the second membrane in yellow and a third membrane in case of MMVs in orange. These membranes are primarily derived from the Golgi; E: An interconnected network of ER-derived DMVs is found in SARS-CoV infected cells. The ER is colored in light-brown, interconnected outer membranes of DMVs in yellow and DMV inner membranes in blue; F: HCV-induced DMVs protruding from the ER (dark-brown). Outer membranes of DMVs are shown in light-brown and inner membranes in orange. Images are modified with permission from ©2007 Kopek et al[24] Plos Biol (A); ©2010 Elsevier Inc.[8] (B); ©2009 Elsevier Inc.[10] (C); ©2012 American Society for Microbiology[26] (D); ©2008 Knoops et al[11] Plos Biol (E); ©2012 Romero-Brey et al[28] Plos Pathog (F).