Reviews & Analysis

In photosynthesis, the plant photosystem II uses the energy in sunlight to oxidize water. The high-resolution structure of this crucial supercomplex has now been obtained using cryo-electron microscopy. See Article p.69

Ashes of ancient meteors recovered from a 2.7-billion-year-old lake bed imply that the upper atmosphere was rich in oxygen at a time when all other evidence implies that the atmosphere was oxygen-free. See Letter p.235

The enzyme RNA polymerase II, along with several transcription factors, initiates DNA transcription. Analyses reveal the structures involved in this process in human and yeast cells at high-resolution. See Articles p.353 & p.359

Emergent quanta of momentum and charge, called quasiparticles, govern many of the properties of materials. The development of a quasiparticle collider promises to reveal fundamental insights into these peculiar entities. See Letter p.225

Neuroscientists are increasingly using virtual reality to facilitate studies of animal behaviour, but whether behaviour in the virtual world mimics that in real life is a matter for debate. Here, scientists discuss the strengths and limitations of the approach.

Both nuclear genes and genes in organelles called mitochondria are involved in the assembly of the cellular energy-producing machinery. RNA-translation programs that coordinate the two systems have now been identified. See Article p.499

If organic molecules were trees, then the numerous carbon–hydrogen bonds within them would be leaves. A catalyst that targets one 'leaf' out of many similar other ones looks set to be a huge leap for synthetic chemistry. See Letter p.230

Palaeoclimatic evidence of monsoon rainfall dynamics across different regions and timescales suggests that monsoon systems exhibit substantial regional variation; meridional temperature gradients are a major driver of monsoon variability, but these gradients are influenced by other, interacting forcing mechanisms, making predictions of future changes in monsoon rainfall highly uncertain.

Describing the motion of three or more bodies under the influence of gravity is one of the toughest problems in astronomy. The report of solutions to a large subclass of the four-body problem is truly remarkable.

Analysis of a sensory neural circuit in the roundworm Caenorhabditis elegans reveals that its wiring is sex-specific, and arises through the elimination of connections that are originally formed in both sexes. See Article p.206

The highly precise atomic clocks used in science and technology are based on electronic transitions in atoms. The discovery of a nuclear transition in thorium-229 raises hopes of making nuclear clocks a reality. See Article p.47

The way in which ketamine exerts its antidepressant effects has been perplexing. Evidence that a metabolite of the drug is responsible, and acts on a different target from ketamine, might be the key to an answer. See Article p.481

The early stages of human development are normally hidden within the womb, but improved techniques for culturing embryos from the blastocyst stage promise to make these steps easier to investigate. See Letter p.251

Membranes have been prepared with a cracked coating that prevents them from drying out in low-humidity conditions — a boon for devices, such as fuel cells, that need hydrated membranes to function. See Letter p.480

Salamanders can regenerate several of their organs, including amputated limbs. Analysis of a Mexican salamander shows that crosstalk between two signalling molecules regulates limb regeneration. See Letter p.407

Insects readily evolve resistance to insecticidal proteins that are introduced into genetically modified crop plants. Continuous directed evolution has now been used to engineer a toxin that overcomes insect resistance. See Article p.58

The microorganisms that colonize pregnant mice have been shown to prime the innate immune system in newborn offspring, preparing them for life in association with microbes.

A mathematical technique has now been developed that reveals the underlying dynamics of time-dependent data collected with extreme temporal uncertainty, without using additional, costly instrumentation. See Letter p.471

Certain sequence variants of the α-synuclein gene are linked to the risk of Parkinson's disease. An analysis of these variants using gene-editing technology provides a possible explanation for this increased risk. See Letter p.95