Figure. Electron microscopy images of thin sections and partially purified virions from cells infected with coronavirus or a virus tentatively associated with the endemic Balkan nephropathy (EBN). A and B. Electron microscopy images of thin sections of swine testicle cell infected with porcine transmissible gastroenteritis coronavirus (TGEV), showing virus binding to cell membrane at 8 h postinfection (A) or immature TGEV virions in the Golgi cisternae (C). B and D. Micrographs of thin sections of Vero cells infected with the virus tentatively associated with EBN at 12 h postinfection. B. The presence of EBN virions in the cytoplasm of the infected cells is indicated by arrows. D. Disorganization of the cytoplasmic membranous system in EBN-infected Vero cells. Electron microscopy images of concentrated TGEV (E) or EBN (F) virions negatively stained with 2% uranyl acetate. Bars in panels A–F represent 50 nm.