Articles in 2012

Single-molecule and ensemble assays are used to show that large T antigen, the replicative DNA helicase of the simian virus 40 (SV40), unwinds DNA as a single hexamer by steric exclusion and is able to bypass covalent DNA–protein crosslinks.

Olfactory receptor neurons of fruitflies are shown to communicate with one another through ephaptic interactions with significant impact on olfactory behaviour; the results indicate that ephaptic effects may be more widespread than previously appreciated.

Simultaneous electrophysiological recordings in hippocampus and neural-activity-triggered whole-brain imaging in the monkey show that most of the cerebral cortex is activated during the fast hippocampal oscillations (ripples), whereas most diencephalic, midbrain and brainstem regions are inhibited; this may function to optimize information transfer from hippocampus to cortex during off-line memory consolidation.

Mice lacking 4E-BP2, an eIF4E repressor, display increased translation of neuroligins; the mice also show autism-related behaviours and alterations in hippocampal synaptic activity, and these are reversed by normalization of eIF4E activity or neuroligin 1 levels.

This study presents the assembly and analysis of the genome sequence of a female domestic Duroc pig and a comparison with the genomes of wild and domestic pigs from Europe and Asia; the results shed light on the evolutionary relationship between European and Asian wild boars.

The results of a series of genetic experiments indicate that Foxo1 has a pivotal, Foxp3-independent role controlling regulatory T-cell function.

Methane oxidation under anaerobic conditions coupled to sulphate reduction is thought to be carried out by a consortium of methanotrophic archaea (ANME) and sulphate-reducing Deltaproteobacteria; here it is shown that ANME alone can mediate the reaction and that the associated bacteria perform disulphide disproportionation, a new microbial sulphur transformation.

Rules that allow the design of strongly funnelled protein folding energy landscapes by relating secondary structure patterns to protein tertiary motifs are used to produce ideal protein structures stabilized by completely consistent local and non-local interactions.

The structure of the bacteriophage transposase MuA bound to DNA sequences that mimic both the transposon ends and the target DNA ends is solved; the picture of this synaptic complex illustrates the intricacy of Mu transposition, and exposes the architectural diversity among DDE recombinases in complex with substrate DNAs.

A general method of creating colloidal particles that can self-assemble into ‘colloidal molecules’ is described: surface patches with well-defined symmetries are functionalized using DNA with single-stranded sticky ends and imitate hybridized atomic orbitals to form highly directional bonds.

This report from the 1000 Genomes Project describes the genomes of 1,092 individuals from 14 human populations, providing a resource for common and low-frequency variant analysis in individuals from diverse populations; hundreds of rare non-coding variants at conserved sites, such as motif-disrupting changes in transcription-factor-binding sites, can be found in each individual.

Oxygen reduction occurring in the surface layer of marine sediments can be coupled to sulphide oxidation in deeper anoxic layers; it is now shown that the electron transfer is mediated by filamentous bacteria acting like living electrical cables.

Mutations in mitochondrial DNA cause a wide range of disorders in humans, with a high prevalence; here it is shown that the nucleus of an affected woman’s egg could be inserted into healthy donor egg cytoplasm by spindle transfer, allowing the birth of healthy offspring.

Exome sequencing and copy number analysis are used to define genomic aberrations in early sporadic pancreatic ductal adenocarcinoma; among the findings are mutations in genes involved in chromatin modification and DNA damage repair, and frequent and diverse somatic aberrations in genes known as embryonic regulators of axon guidance.

The detection of an Earth-mass planet orbiting our neighbour star α Centauri B is reported; the planet has an orbital period of 3.236 days and is about 0.04 astronomical units from the star.

The crystal structures of the histone chaperone DAXX histone-binding domain bound to a histone H3.3–H4 dimer are described; DAXX wraps around the H3.3–H4 dimer and alters its conformation.

An integrated high-resolution genetic, physical and shotgun sequence assembly of the barley genome, one of the earliest domesticated and most important crops, is described; it will provide a platform for genome-assisted research and future crop improvement.

In models of early life it has been suggested that life and evolution would be more easily achieved if RNA molecules could interact, rather than function independently; here an in vitro system is designed with several RNA fragments that can assemble into a ribozyme, showing that cooperative networks formed by these fragments outcompete self-catalytic RNA fragments.

A study of X-ray crystal structures of the Escherichia coli xylose transporter XylE, which is a bacterial homologue of the human glucose transporters GLUT1–4, complexed with glucose and its analogues yields a framework for understanding the molecular mechanism by which membrane proteins transport glucose and other sugars across cell membranes.

Through the use of a combination of state-of-the-art techniques, different populations of ventral tegmental area dopamine neurons in the mouse are shown to form separate circuits with distinct connectivity: neurons receiving input from the laterodorsal tegmentum and lateral habenula are found to mediate reward and aversion, respectively.