Gene transfer

Single-copy transgene insertion in worms

Methods for making single-copy insertions of transgenes at specific sites in the Caenorhabditis elegans genome have been lacking. Now, Frøkjær-Jensen et al. adapt the Drosophila melanogaster Mos1 transposon for this purpose. They identify genetically neutral intergenic Mos1 insertion sites in the worm genome, and show that mobilization of the transposon and repair of the resulting double-stranded break can be used to create a single-copy insertion of a transgene into the chromosomal site.

Frøkjær-Jensen, C. et al. Nat. Genet. 40, 1375–1383 (2008).

Microarrays

Improving protein detection with Raman

Protein microarrays provide a high-throughput protein identification platform. Typically, fluorescence detection is used as the readout, but fluorescence is prone to background interference and autofluorescence, limiting the sensitivity of microarrays. Chen et al. describe a new, highly sensitive detection method, which uses functionalized single-walled carbon nanotubes as multicolor Raman scattering labels. The Raman-based detection system improves sensitivity by 1,000-fold over fluorescence, facilitating new research and clinical applications of protein microarrays.

Chen, Z. et al. Nat. Biotechnol., advance online publication 26 October 2008.

Systems biology

Digital zebrafish embryos

The global movements of cells during embryogenesis have not as yet been tracked in a vertebrate model. Using their newly developed digital scanned laser light sheet fluorescence microscopy, in which a thin beam of light is rapidly scanned through a specimen, Keller et al. track the movement of all cells over a 24-hour period of zebrafish development. The resulting digital embryos will constitute a useful resource for zebrafish biologists.

Keller, P.J., et al. Science, published online October 9, 2008.

Metabolomics

Profiling protein-metabolite interactions

The small molecules of the 'metabolome' have important roles in cellular processes by regulating protein function. Tagore et al. describe an approach to identify protein-metabolite interactions. They immobilize the protein of interest on a solid support and incubate it with a cellular metabolite mixture. Metabolites that bind to the protein are eluted and analyzed by a global liquid chromatography–mass spectrometry platform for identification.

Tagore, R. et al. J. Am. Chem. Soc. 130, 14111–14113 (2008).

Spectroscopy

Taking temperature with MRI

Something as basic as temperature is actually quite difficult to determine in vivo. Existing magnetic resonance imaging–based methods are subject to inaccuracies caused by inhomogeneous magnetic fields in tissues. Galiana et al. now describe a new magnetic resonance method for highly accurate in vivo temperature imaging, based on new pulse sequences for intermolecular multiple quantum coherence detection that reduce the effects of physiological noise.

Galiana, G. et al. Science 322, 421–424 (2008).