Genomics

Whole-genome patterns of common DNA variation in three human populations

In an effort to generate a more comprehensive and relevant collection of single-nucleotide polymorphism (SNP) information, Hinds et al. conducted a detailed analysis of three distinct populations of unrelated individuals of European, African and Asian ancestry. They present the findings from their initial analysis of the extent of variation for over 1.5 million SNPs, data which they have made publicly available online.

Hinds, D.A. et al. Science 307, 1072–1079 (2005).

Imaging and Visualization

Near infrared–emissive polymersomes: self-assembled soft matter for in vivo optical imaging

The development of a versatile and stable reagent with near-infrared fluorescence would be a considerable boon for imaging studies that require deep penetration of living tissues. Ghoroghchian et al. describe the generation of self-assembling polymersomes that incorporate an oligo(porphyrin)-based near-infrared fluorophore and demonstrate the potential of these bodies for in vivo imaging applications.

Ghoroghchian, P.P. et al. Proc. Natl. Acad. Sci. USA 102, 2922–2927 (2005).

Proteomics

Interaction network containing conserved and essential protein complexes in Escherichia coli

By adapting the yeast-based tandem affinity purification (TAP) technique for use in E. coli, Butland et al. have assembled a detailed interaction network that describes the associations between nearly 650 different bacterial proteins, confirming several predicted associations and identifing many interaction 'hubs' that seem to be broadly conserved among prokaryotes.

Butland, G. et al. Nature 433, 531–537 (2005).

RNA Interference

A universal plasmid library encoding all permutations of small interfering RNA (siRNA)

Many current RNA interference (RNAi) studies begin with a target gene and attempt to identify a suitable siRNA. Chen et al. present a tool for researchers who want to work in the reverse direction—a library encoding nearly every possible 19-nucleotide siRNA sequence—and describe how such libraries could prove valuable for conducting phenotype-driven RNA interference studies.

Chen, M. et al. Proc. Natl. Acad. Sci. USA 102, 2356–2361 (2005).

Microbiology

Screening for quorum-sensing inhibitors (QSIs) by use of a new genetic system, the QSI selector

Genes involved in quorum sensing, the process by which many bacteria organize their pathological progression in response to population density, are now recognized as an important potential antibiotic target. Rasmussen et al. demonstrate several novel genetic screens for the identification of QSIs.

Rasmussen, T.B. et al. J. Bacteriol. 187, 1799–1814 (2005).