Articles in 2009

They are the quintessential drug target—but the dynamic structures and highly elaborate mechanisms of G protein–coupled receptors continue to keep experts in both industry and academia on their toes.

Single-molecule sequencing of poly(A)-tailed chromatin immunoprecipitated DNA proves equal in sensitivity and accuracy to amplification-based sequencing technologies and allows analysis of samples sizes as small as 50 pg.

Staining with a mitochondrial dye permits high-purity isolation of cardiomyocytes from embryonic and induced pluripotent stem cells of several species, without genetic modification.

A degradation pathway found in plants, dependent on the hormone auxin, can be transplanted and harnessed to induce rapid and reversible target protein degradation in both yeast and animal cells.

Microsources positioned with holographic optical tweezers can establish a highly localized, three-dimensional chemical gradient that allows the manipulation of polarization and migration in single cells.

Tissue-specific expression of microRNA sponges allows precise regulation of microRNA activity in living flies. The authors investigate the role of miR-8 in the formation of neuromuscular junctions in detail.

Methods for automated fluorescence imaging allow high-throughput examination of reporter expression patterns in zebrafish embryos. They are applied to mapping promoter-enhancer interactions in this organism.

An improved version of the GCaMP genetically encoded calcium indicator, called GCaMP3, has higher calcium affinity and increased baseline fluorescence, dynamic range and stability. GCaMP3 performs better than existing genetically encoded calcium indicators in several assays and organisms, including in vivo imaging of neuronal signaling in worms, flies and mice.

Neuronal stimulation with channelrhodopsin-2 is combined with calcium fluorescence imaging to study neural connections in intact Caenorhabditis elegans.

Fusion of the genetically-encoded calcium indicator GCaMP2 to synaptophysin localizes the sensor to neuron presynaptic terminals and conveys linear responsiveness over a wider range of spike frequencies. The sensor allowed measurement of synaptic activity caused by spiking as well as graded voltage signals during in vivo imaging in zebrafish.

With a modified polymerase and optimized oligonucleotide chemistry, Helicos' single-molecule sequencer takes on RNA.

Researchers use atomic force microscopy to image the chemical structure of the small molecule pentacene, with atomic resolution.

Certain yeast previously assumed to lack RNA interference machinery instead have alternative enzyme variants, which can in turn be transplanted to truly deficient species.

By monitoring the size-dependence of particle distribution in the lamellipodium, fluid flow in moving cells can be measured.

A new in vivo imaging strategy produces detailed maps of tumor microvasculature and lymphatic vessels without injected labels.