Cover photograph (Copyright © 2004, American Society for Microbiology. All Rights Reserved.): African swine fever virus is a large enveloped DNA virus that assembles in perinuclear factories close to the microtubule organizing center and uses microtubules to reach the cell surface. This image shows viruses closely aligned on microtubules. Viruses are stained red, using antibodies recognizing viral structural protein pE120R, and DNA in the virus factory is stained with DAPI (blue). The green signal shows the distribution of microtubules. (See related article on page 7990.)