Cover photograph (Copyright © 2005, American Society for Microbiology. All Rights Reserved.): Double-labeled immunofluorescent images of the tachyzoite (top left), mature schizont (top center), merozoite (top right), macrogamete (bottom left), and tissue cyst (bottom right) of Toxoplasma gondii. The sections were stained with an antibody to enoyl reductase (green) to illustrate the appearance and location of the apicoplast during in vivo development. The second antibody (red) varied with the parasite stage being examined, and all stages were counterstained with DAPI (4`,6`-diamidino-2-phenylindole) (blue) to identify the nuclei. (See related article on p. 814.)