Biosensors

Direct molecular detection of nucleic acids by fluorescence signal amplification

PCR amplification is a typical component of most high-sensitivity DNA detection strategies, but Ho et al. present an alternative approach that relies on a specially designed optical polymer for fluorescence-based detection of target DNA sequences. This method is capable of detecting DNA at zeptomolar concentrations within five minutes without enzymatic amplification.

Ho, H.A. et al. J. Am. Chem. Soc.; published online 18 August 2005.

Gene regulation

Tuning genetic control through promoter engineering

Using error-prone PCR to introduce mutations into a constitutively active promoter, Alper et al. demonstrate an approach for the generation and analysis of libraries of promoters with varying transcriptional output levels. The authors suggest this method could be useful for more precise manipulation of gene expression or for studying sequence determinants of promoter activity.

Alper, H. et al. Proc. Natl. Acad. Sci. USA 102, 12678–12683 (2005).

Chemical Biology

Combinatorial polyketide biosynthesis by de novo design and rearrangement of modular polyketide synthase genes

Natural polyketide compounds perform a wide variety of biological functions, and the ability to synthesize novel polyketides could prove valuable. This process is complicated, however, and requires the coordinated action of multiple enzyme modules. Menzella et al. describe swappable enzymatic 'cassettes' that promise to simplify the combinatorial synthesis of new polyketides.

Menzella, H.G. et al. Nat. Biotechnol.; published online 14 August 2005.

Proteomics

Large-scale identification of yeast integral membrane protein interactions

The difficulties of working with membrane proteins have limited the ability of researchers to study this segment of the interactome. Miller et al. performed a split-ubiquitin two-hybrid interaction screen and analyzed their data with a support vector machine 'learning algorithm' in an effort to more confidently assess the associations of integral membrane proteins in yeast.

Miller, J.P. et al. Proc. Natl. Acad. Sci. USA 102, 12123–12128 (2005).

Genomics

The transcriptional landscape of the mammalian genome

Researchers from the FANTOM Consortium and RIKEN have collaborated in an extensive analysis of the mouse transcriptome, yielding the surprising finding that the mouse genome seems to contain many more genes than previously predicted: an estimated 181,047 transcripts generated from dense 'transcriptional forests' encompassing more than 60% of the genome.

The FANTOM Consortium et al. Science 309, 1559–1563 (2005).