Transmission Electron Micrograph (TEM) reveals some of the ultrastructural morphology exhibited by two Adenovirus-2 virions. The sample had been pelleted, thereby, concentrating the viral particles prior to viewing under the microscope. Visible at this high magnification are the capsomeres, which in this case were hexagonally-shaped, also called hexons, and which together comprised the outer covering of the adenovirus known as a capsid. These adenoviruses displayed an icosahedral symmetry, which means that the shape was characterized by 12 vertices, and 20 facets. Each virion was 70nm-80nm, and exhibited no spikes. Canine adenovirus 2 (CAdV-2) is one of the potential causes of kennel cough. Core vaccines for dogs include attenuated live CAdV-2, which produces immunity to CAdV-1 and CAdV-2. CAdV-1 was initially used in a vaccine for dogs, but corneal edema was a common complication. |