Cover photograph (Copyright © 2006, American Society for Microbiology. All Rights Reserved.): Somatic ACT1Δ transformant of Tetrahymena thermophila, immunostained for basal bodies and oral crescents with anticentrin monoclonal antibody 20H5 (gift of Jeffrey Salisbury). This reintegrated cell results from failure of separation in two successive attempts at cytokinesis. The less distorted posterior furrow is likely to be the more recent one. The three oral apparatuses are laterally offset relative to each other, as a probable consequence of abortive attempts at daughter cell separation. (See related article on page 555.)