Research articles

Cohesin, which tethers sister chromatids together, is found to be cleaved by separase after DNA damage, resulting in cohesin dissociation and allowing for post-replicative repair of DNA double-strand breaks.

Upregulation of gene transcription in stressed cells can lead to clashes between the transcription and repair machineries; here, a stress-activated protein kinase (SAPK), Hog1, is shown to coordinate these two processes in yeast.

YAP has previously been identified as an oncogene that promotes cell growth, but now it is shown to restrict stem cell expansion during regeneration in the mouse intestine, suggesting that it may function as a tumour suppressor in colon cancer.

First-principles calculations on a huge configuration space of four different binary alloy systems reveal that stiffness and heat of formation are negatively and linearly correlated.

Studying six vespertilionid bat species of different sizes to investigate the reason why smaller bats have higher frequency echolocation calls, a model is put forward that the size/frequency range is modulated by the need to maintain a focused, highly directional echolocation beam.

The icy dwarf planet Makemake has projected axes of 1,430 ± 9 and 1,502 ± 45 km and a V-band geometric albedo larger than Pluto’s but smaller than Eris’s, with no global Pluto-like atmosphere.

Spectroscopic measurements now reveal that at low temperatures, the water in hydrophobic hydration shells has greater tetrahedral order and fewer weak hydrogen bonds than the surrounding bulk water; this structure disappears at higher temperatures and around alcohol chains longer than 1 nanometre.

Analysis of data from forest plants worldwide shows that margins between threshold xylem pressures at which plants suffer damage and the lowest xylem pressures experienced are small, with no difference between dry and wet forests, providing insight into why drought-induced forest decline is occurring in both arid and wet forests.

Vacuolar acidity in yeast is shown to decline with age, and preventing this decrease suppresses mitochondrial dysfunction and extends the lifespan of yeast.

Colloidal Janus spheres in a precessing magnetic field are shown to self-assemble into in-motion microtubes dynamically selected on the basis of synchronization rather than static energy minimization.

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.

Iridoids are a large family of bicyclic natural products that possess anticancer, anti-inflammatory, antifungal and antibacterial activities; here the essential cyclization step in their biosynthesis is identified, opening up the possibility of production of naturally occurring and synthetic variants of iridoids for use in pharmacy or agriculture.

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.

Visual responses during wakefulness are dominated by inhibition, and this inhibition shapes visual selectivity by restricting the temporal and spatial extent of neural activity.

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.

High-speed tracking of effortful responses and neuronal activity in rats during a forced swim test identifies medial prefrontal cortex (mPFC) neurons that respond during escape-related swimming but not normal locomotion, and optogenetics shows that mPFC neurons projecting to the brainstem dorsal raphe nucleus, which is implicated in depression, modulate this behavioural response to challenge

DNA damage or replication stress induces the activation of checkpoint kinases, pausing the cell cycle so that DNA repair can take place; checkpoint activation must be regulated to prevent the cell-cycle arrest from persisting after damage is repaired, and now the Slx4–Rtt107 complex is shown to regulate checkpoint kinase activity by directly monitoring DNA-damage signalling.

Critical transitions in experimental and theoretical systems can be anticipated on the basis of specific warning signs, with ‘critical slowing down’ being the best studied; long-term data from a real system, a Chinese lake, now show that a flickering phenomenon can be observed up to 20 years before the critical transition to a eutrophic state.

FusKR, a fucose-sensing two-component system, has been identified in enterohaemorrhagic E. coli, linking fucose utilization and virulence factor gene expression and providing insight into how sensing of a host signal can facilitate bacterial colonization.

A whole-genome and transcriptome analysis of 20 human induced pluripotent stem-cell lines shows that reprogramming does not necessarily add de novo copy number variants to what is already present in the somatic cells from which they originated.