Cover photograph (Copyright © 2007, American Society for Microbiology. All Rights Reserved.): Aspergillus nidulans asexual reproductive structure, the conidiophore, viewed by differential interference contrast and fluorescence microscopy. Fixed cultures were stained with Hoescht 3325 to label nuclei. Conidiophore development proceeds by a well-defined pathway that results in the production of round conidiospores each containing a single nucleus. (Images acquired by Yainitza Hernandez-Rodriguez, Department of Plant Biology, University of Georgia; reproduced with permission.) (See related article on page 1697.)