Cover photograph (Copyright © 2007, American Society for Microbiology. All Rights Reserved.): Coiled hyphae develop from the early mating structures of the fungus Histoplasma capsulatum. The structure shown was formed during a cross between two clinical isolates of H. capsulatum. The isolates were determined to be of opposite mating type based on the idiomorph of the mating type locus present in each strain. The merged fluorescent/phase image shows the cell wall stained with solophenyl flavine (green) and nuclei stained with propidium iodide (red). (See related article on page 616.)