Cover photograph (Copyright © 2003, American Society for Microbiology. All Rights Reserved.): Wild-type and Himar1 transposon-derived pigmentation mutants of Rhodococcus equi. Wild-type R. equi is salmon colored due to the production of γ-carotene. Insertions that disrupt carotenoid biosynthesis produce mutants of various colors. Wild-type bacteria and three such mutants were pooled and plated, producing the mixed colonies observed here. (See related article on page 2644.)