Research articles

The mechanism responsible for the toughness of nacre, the hierarchical iridescent material in seashells, is still unknown. Espinosa and colleagues show that the waviness of its tablets leads to interfacial hardening, and ultimately to energy dissipation, when the material is stressed.

Little is known about the reproductive ecology of freshwater eels. In this article, the authors describe the capture of two species of eels together with eggs and newly hatched larvae, and suggest that spawning takes place during the new moon at shallower depths than previously thought.

Microvesicles containing RNA are released from tumour cells. Here, the authors show that microvesicles released from tumour cells in culture have amplified levels of thec-Myconcogene, which is also found in the cell of origin, suggesting that microvesicles could be used as biomarkers.

The origin of the Atlantic Multidecadal Oscillation, a semi-periodic variability of sea-surface temperature, is unknown. Knudsenet al.show that 55- to 70-year climate oscillations existed throughout the last 8,000 years, suggesting that the Atlantic Multidecadal Oscillation is a permanent feature of the Holocene climate induced by internal ocean variability.

Uridines at the wobble position of transfer RNA anticodons are usually modified to allow efficient decoding of messenger RNA codons. In this study, ALKBH8 is shown to be a bifunctional transfer RNA modification enzyme required for the formation of a novel diastereomeric pair of modified wobble uridines.

HrpR and HrpS enhancer-binding proteins ofPseudomonas syringae activate σ⁵⁴-dependent transcription of the HrpL promoter and are required for type-three secretion pathogenicity. Here, the authors demonstrate that, despite being co-regulated, HrpR and HrpS each have distinct functions for activating σ⁵⁴.

Interfacing neurons with artificial functional materials could aid the development of neurological prosthetic devices. Here, primary neurons are incorporated into a polymer layer without adversely affecting their properties; the advance may contribute to the development of artificial retinas.

Error correction in quantum computing can be implemented using transversal gates, which in turn rely on the availability of so-called magic states. The authors experimentally show that it is possible to improve the fidelity of these states by distilling five of them into one.

Seahorses evolved from pipefish, which have a remarkably different body shape. Here, by examining seahorse feeding behaviour and using a mathematical model, Van Wassenberghet al. demonstrate that the head, neck and trunk posture of the seahorse allows for the effective capture of their prey.

Distinguishing closely related molecules using chemosensor materials is a continuing challenge. Here, an entangled porous coordination polymer is developed, which confines volatile organic compounds, and allows photoluminescence-based distinction of structurally similar aromatic molecules.

Extinction cascades in food-web networks pose a challenge for ecosystem conservation. Sahasrabudhe and Motter use modelling to show that the removal or suppression of a species can compensate for the extinction of another one, and thus, reduce the likelihood of an extinction cascade.

Stem cell-mediated regenerative medicine requires the development of defined culture systems for the maintenance of human embryonic stem cells. Here, feedback system control is used to identify a combination of three small molecule inhibitors that enables long-term human embryonic stem cell maintenance.

Microorganisms are abundant in many environments and understanding their dispersal between ecosystems is important for ecology and conservation. These authors demonstrate that cyanobacterial populations are specific to hot or cold deserts and that gene flow between different populations does not occur.

Dopaminergic neurons, which are affected in neuronal diseases, have important roles in modulating behaviour, cognition and physiology. In this study, the authors map every projection for each type of dopaminergic neuron in zebrafish larvae, which may help to understand neurological disease.

ThePlasmodium falciparum parasite that causes malaria has a complex life cycle in human erythrocytes. Using time-lapse three-dimensional imaging, the authors show the intraerythrocytic stages of the parasite and provide new insight into the export of P. falciparumproteins to Maurer's clefts.

Interspecies transmission of influenza A viruses requires adaptation of the viral polymerase to the host importin-α. Here, the polymerase subunit PB2 and the nucleoprotein of avian viruses are found to require importin-α3, whereas mammalian viruses are shown to require importin-α7.

Antarctic bottom water is important for the global climate system, but its main source in East Antarctica was altered recently because of calving of the Mertz Glacier Tongue. The authors model this event and find large changes in dense water exports from the region.

Some organisms produce unequal numbers of male and female progeny, but the mechanics of skewed of sex ratios are largely unknown. Here, the authors describe alterations in X-chromosome segregation and cytoplasmic partitioning during spermatogenesis that together explain the distorted sex ratio in a nematode species.

The activity of serine proteases, including CAP1/Prss8, is altered in some human skin disorders; however, the downstream effectors of these proteins are relatively unknown. Here, using animal models, the authors show that protease-activated receptor-2 is a critical component of the CAP1/Prss8 signalling cascade.

The control of cell fate and apoptosis is a continuing challenge in synthetic biology. In this study, systems are developed in which an intracellularly expressed genome-encoded protein simultaneously achieves up- and downregulation of two distinct apoptosis pathways.