Contents

19 July 2013
Vol 341, Issue 6143

About The Cover

Cover image expansion

COVER Enhanced transmission electron microscopy image of a "Pandoravirus" particle (length: 1.2 micrometers). Despite obeying all criteria to discriminate viruses from cells (no ribosome, no adenosine triphosphate production, no division), these Acanthamoeba viruses, unrelated to previously recognized virus families, exhibit genomes of up to 2.5 megabases, encoding more genes than some microsporidia. See pages 226 and 281. Image: O. Poirot/Structural and Genomic Information Laboratory, CNRS Aix-Marseille Université