Contents

03 September 2004
Vol 305, Issue 5689

About The Cover

Cover image expansion

COVER The phenomenon now known as RNA interference (RNAi) was first uncovered as a sequence-specific gene silencing response provoked by the introduction of exogenous multicopy transgenes into petunia. This resulted in flowers with two-toned color patterns, as shown here. The crystal structure of Argonaute, a signature component of the RNAi effector complex, is shown with its PAZ domain in blue and PIWI domain in purple. See pages 1409, 1434, and 1437. [Petunia image, R. Jorgensen; ribbon diagram, L. Joshua-Tor]