Small-molecule suppression of zebrafish mutants. Using a chemical genetic screen, Stern et al. (p 366) identified persynthamide, a compound that suppresses the crash&burn (crb) mutation in zebrafish by inhibiting S phase of the cell cycle (see also News & Views by Sidi & Look, p 351). The image shows zebrafish embryos immunostained with an antibody specific for phosphorylation of Ser10 of histone H3, a marker of mitotic cells. Cover art by Erin Boyle, based on images provided by Christian Straub.

Migratory pheromones in the sea lamprey. Using a combination of natural product chemistry, spectroscopic methods and bioassays, Sorensen et al. (p 324) show that a mixture of previously unknown sterol compounds serves as a potent pheromonal attractant in the sea lamprey, one of the earliest known vertebrates (see also News & Views by Dittman, p 316). The cover shows an adult sea lamprey. Cover art by Erin Boyle based on a photo provided by Peter Sorensen, courtesy of the Minnesota Agricultural Experiment Station.

Streptomyces genome mining. Lautru et al. (p 265) used a bioinformatics approach to isolate a new siderophore natural product from Streptomyces coelicolor (see also News & Views by Bachmann, p 244). The cover shows the structure of the gallium complex of coelichelin with colonies of Streptomyces coelicolor. Cover art by Erin Boyle based on images provided by Dr. Gregory L. Challis and Dr. Tobias Kieser.

Seeing signalosomes. Ianoul et al.(p 196) use near-field scanning optical microscropy (NSOM) to visualize nanoscale β-adrenergic receptor clusters in the membranes of murine cardiac myocytes (see also News & Views by Park & Palczewski, p 184). The cover shows fluorescence and NSOM images of neonatal mouse cardiac myocytes stained for the β2-adrenergic receptor (red) and the nuclei (blue). Cover art by Erin Boyle based on images provided by John Pezacki.

Promiscuous inhibitor aggregates. Feng et al. show (p 146) that many 'drug-like' molecules form aggregates at high concentrations, which cause non-specific enzyme inhibition. They developed a high-throughput screen to select against such promiscuous inhibitors in the lead generation process (see also News & Views by Sawyer, p 125). Cover art by Erin Boyle based on images provided by Brian Feng.

A cellular path to necrosis. Degterev et al. identify (p. 112) a small molecule that specifically inhibits death - induced necrosis, suggesting that a precise cellular pathway leads to necrotic cell death (see also News & Views by Wallach, p 68). Cover art by Erin Boyle based on electron micrographs provided by Junying Yuan.

General acid catalysis by a ribozyme. Das & Piccirilli show (p 45) that a hepatitis delta virus ribozyme uses a cytosine nucleobase as a general acid catalyst of phosphodiester bond cleavage (see also News & Views by Strobel, p 5). Cover art by Lewis Long, watercolor and ink on paper.