Volume 7 Issue 5, May 2010

By mapping the underbelly of human genomes, researchers open new questions.

Researchers evolved a ribosome that efficiently decodes quadruplet codons, thus opening up the possibility of genetically incorporating multiple unnatural amino acids into proteins.

New software tools help take the pain out of working with huge three-dimensional image datasets and aid in mapping neuronal networks.

A systematic map of pair-wise physical interactions among mammalian transcription factors will enable studies of transcriptional control in development and disease.

Monitoring the activity of neurons in vivo in the freely behaving zebrafish larvae is now possible using bioluminescence, an approach with great potential for unveiling how neuronal networks control behavior.

A study of the genetic variation in 17 human embryonic stem cell lines shows hundreds of changes, some associated with cancer.

Whole-genome sequencing of DNA from two children with Mendelian disorders and from their healthy parents allows efficient correction of sequencing errors and the identification of causal genes.

With microfluidics and multiplexing, researchers can get more information from PCR products in less time and with fewer reagents.

Improved and easy-to-implement methods for precise fitting of curves to Poisson-distributed data—such as photons from single emitters—reach the limits of fitting precision.

The super-SILAC approach facilitates the quantitative analysis of human tumor tissue proteomes.

Silicon-based microscales allow real-time measurements of the growth rate of single cells and open up interesting perspectives for the study of mass biogenesis at the cellular level.

Paired-end sequencing of human genomic DNA reveals at least 2.8 Mb of new sequence at 720 distinct loci. Complete sequencing of 1.67 Mb at 192 loci reveals extensive copy-number variation and provides a resource for genotyping these 'missing' sequences.

An iterative algorithm implemented on a graphics processing unit determines maximum likelihood estimates of the positions of isolated fluorophores at a rate of 10⁵ localizations per second and allows real-time generation of super-resolution images with high precision.

A theoretical and experimental treatment of fitting methods for localizing the centers of diffraction-limited spots is presented. Use of an analytical point spread function shows that maximum likelihood fitting is superior to both unweighted and weighted least squares Gaussian fitting.

Robust and accurate quantification of human tumor tissue proteomes is made possible by combining the tissue sample with an 'internal standard' mixture of five relevant, stable isotope–labeled cell lines, followed by mass spectrometry analysis.

A microfluidic device containing a suspended microchannel resonator capable of measuring the mass of microscopic objects with femtogram resolution allows determination of bacteria, yeast and mammalian cell growth rates in less than one cell cycle by repeated measurement of the buoyant mass of single growing cells.

Traptavidin, a streptavidin mutant with about tenfold lower 'off' rate for biotin than streptavidin itself, has increased mechanical strength and thermostability. It should find use in a diversity of applications in which the dissociation of streptavidin can be a limitation.

A combination of padlock probes and rolling circle amplification allows single nucleotide accuracy for transcript detection in individual cells.

Limitations in scanning speed have made it difficult for two-photon imaging to provide accurate temporal information on neuronal signaling. Refinements to random-access scanning using acousto-optic deflectors and an automated algorithm for reconstructing complex spike trains allowed in vivo high-speed optical recording of spiking activity in neuronal populations in the mouse neocortex.

A conditional gene expression system in Caenorhabditis elegans is reported. It should permit the generation of temperature-sensitive alleles for most genes.