Cover photograph (Copyright © 2001, American Society for Microbiology. All rights reserved.): Phenotypic characterization of Streptomyces coelicolor B22 and its transconjugants with alkali treatment. Aliquots were taken from four liquid cultures, transferred into test tubes, and then mixed with either water (panels clear at top) or 1 N aqueous ammonia (colored panels). The eight panels shown represent the central sections of each of the test tubes, with the darker section at the bottom of each panel being the settled mycelia. (See related article on page 3247.)