Cover photograph (Copyright © 2008, American Society for Microbiology. All Rights Reserved.): When grown in static liquid medium, many marine roseobacters show an unusual group of phenotypes: formation of rosettes (background), production of a yellow-brown pigment, and synthesis of the antibiotic tropodithietic acid (TDA). Several of the genes responsible for TDA biosynthesis are on a ca. 130-kb plasmid. Shown from top to bottom: Silicibacter sp. strain TM1040 grown under shaking culture conditions (left flask) and static conditions (right flask) and a nutrient agar plate showing colonies of the wild type (left), a spontaneous Tda⁻ mutant (top), and a transposon insertion in tdaE (bottom right), one of a dozen genes determined to be necessary for TDA biosynthesis. (See related article on page 1535.)