The arthropod Dscam genes utilize mutually exclusive splicing of large clusters of variable exons to generate tens of thousands of receptors that function in the nervous and immune systems. Work by Graveley and colleagues now gives insight into regulation of Dscam exon choice. Traffic Light Tree (1998), by Pierre Vivant, symbolizes the role of hrp36 in repressing inclusion of multiple alternative exons in these events. Photo taken and kindly provided by Simon Kimber (www.flickr.com/simonkimber).pp 1334-1140

The cover, titled "Crosstalk", represents an artist's view of concepts such as information compression and multi-layered communication at work in chromatin. "Crosstalk" is an original work of art commissioned from Colleen Buzzard (http://www.colleenbuzzard.com). Archival materials on acid-free papers.pp 986–1055, Primer p 1110

SNARE proteins are central components of the membrane fusion machinery. Surface forces apparatus experiments between membraneembedded neuronal SNAREs reveal the dynamics and energetics of SNARE assembly across lipid bilayers. The pairing of arms symbolizes the structure and force generated during the association of cognate SNAREs. Computer graphics cover art by Daniel de Fuenmayor.(http://www.fmixlab.com).pp 890-896, News and Views p 880

Fluorescent labeling techniques have allowed observation of RNA Polymerase II transcription in vivo and in real time. The cover shows such a labeled cell with the transcribing locus highlighted in yellow. Cover by Robert Singer and colleagues.pp 796-806, News and Views p 788

The Histone H3 N-terminal tail can be multiply methylated at different lysine residues. The structures of the histone demethylase JMJD2A in complex with peptides give insight into the specificity of histone demethylation. The clover and trefoil symbol represent JMJD2A's preference for acting on trimethylated lysines. Cover by Erin Boyle.pp 689-695 | News and Views p 682

Tumor cells using the alternative telomere lengthening pathway are examined by Potts and Yu, who find that telomeres are targeted to PML bodies via SUMOylation of multiple telomeric proteins. Darts represent telomeres being targeted to a PML body represented by the bullseye. Photo by Bimarto Sasri, from iStockPhoto.com. pp 581-590 | News and Views p 570

Inagaki and colleagues present solution structures of CRKI, CRKII and phosphorylated CRKI, which, together with mutational analyses, reveal the structural basis for the very different biological activities of these CRK splice forms. Matisse-inspired renderings represent CRK conformations. Cover by Erin Boyle.pp 503-510 | News and Views p 465

Expansion of polyQ tracts is associated with neurological disorders. New data from Bjorkman and colleagues suggest that polyQ expansion (represented here as vines) generates multiple sites for normal polyQ binding proteins (leaves), which may lead to aberrant protein-protein interactions. Photo by Pingwei Li, with thanks to Dr. Sharon Banister of the Texas A&M University horticulture green house.pp 381-387

Two GAD isoforms are responsible for GABA synthesis. Whisstock and colleagues solve the structure of the GAD isoforms, finding that a tethered loop in the constitutively active GAD67 is mobile in GAD65 and involved in its auto-activation. The pair of leaves represents the GAD dimer with the curled edge reminiscent of the catalytic loop that protects the active site in GAD67. Artwork by Pascal Ouellet (www.bigoudi.ca). pp 280-286

Work by Hurley and colleagues reveals interactions between the ESCRT protein Alix and HIV-1 Gag p6 that are important for HIV-1 budding. The image of a budding peony, the subject of a photograph entitled "Spring Noir", is evocative of the viral budding process. Photograph kindly provided by Elisabeth Feldman (http://www.flickr.com/photos/hurleygurley).pp 194-199

The cholesteryl ester transfer protein (CETP) shuttles lipids between lipoproteins. The crystal structure of CETP reveals a lipid-bound tunnel across the protein core, represented here by a tunnel through an underwater aquarium.pp 106-113 | News and Views p 95

DGCR8 is an RNA binding protein involved in the processing of primary microRNA transcripts. Guo and colleagues now show that DGCR8 binds heme. Upon heme binding, autoinhibition mediated by the heme-binding region of DGCR8 is alleviated, promoting primary microRNA processing. The heme molecule is represented within snowflakes on the cover image. Cover by Erin Boyle. pp 23-29