Volume 531 Issue 7595

Editorials

Cultural conundrum p.413

The Chinese government’s professed commitment to transparency and responsiveness has had a rocky start. That bodes ill for the desire to attract the best science brains from around the world.

doi: 10.1038/531413a

Siren call p.413

Now that gravitational waves have been discovered, it is time to put them to use.

doi: 10.1038/531413b

Power of the pen p.414

Scientists must unite to stop Turkey from removing the right to freedom of expression.

doi: 10.1038/531414a

News

News Features

News & Views

Lost memories found p.450

Enhancing synaptic connections between neurons in the brain's hippocampus that are normally activated during memory formation rescues memory deficits in a mouse model of early Alzheimer's disease. See Letter p.508

doi: 10.1038/nature17312

Dispersion explains declines p.451

Migratory birds are declining globally. A broad study of European migratory birds finds that species that disperse widely during the non-breeding season are less likely to be in decline than are species with more restricted dispersion.

doi: 10.1038/531451a

No double bond left behind p.453

Alkenyl halides are some of the most useful building blocks for synthesizing small organic molecules. A catalyst has now allowed their direct preparation from widely available alkenes using the cross-metathesis reaction. See Article p.459

doi: 10.1038/531453a

Viral strategies at sea p.454

The finding that marine environments with high levels of host microbes have fewer viruses per host than when host abundance is low challenges a theory on the relative roles of lysogenic and lytic viral-survival strategies. See Article p.466

doi: 10.1038/nature17303

Signs of a wandering Moon p.455

The presence of ice at two positions on opposite sides of the Moon suggests that the satellite's orientation was once shifted away from its present spin axis — a finding that has implications for the Moon's volcanic history. See Letter p.480

doi: 10.1038/531455a

Corruption corrupts p.456

A cross-cultural experiment involving thousands of people worldwide shows that the prevalence of rule violations in a society, such as tax evasion and fraudulent politics, is detrimental to individuals' intrinsic honesty. See Letter p.496

doi: 10.1038/nature17307

Articles

Direct synthesis of Z-alkenyl halides through catalytic cross-metathesis p.459

One shortcoming of olefin metathesis has been that acyclic alkenyl halides could not be generated efficiently and stereoselectively; but now halo-substituted molybdenum alkylidene species are shown to be able to participate in high-yielding olefin metathesis reactions that afford acyclic 1,2-disubstituted Z-alkenyl halides.

doi: 10.1038/nature17396

Lytic to temperate switching of viral communities p.466

An analysis of 24 coral reef viromes challenges the view that lytic phage are believed to predominate when the density of their hosts increase and shows instead that lysogeny is more important at high host densities; the authors also show that this model is consistent with predator–prey dynamics in a range of other ecosystems, such as animal-associated, sediment and soil systems.

doi: 10.1038/nature17193

Letters

Acceleration of petaelectronvolt protons in the Galactic Centre p.476

Deep γ-ray observations of the Galactic Centre with arcminute angular resolution show traces of petaelectronvolt protons within the central ten parsecs of our Galaxy; the accelerator of these particles could have provided a substantial contribution to Galactic cosmic rays in the past.

doi: 10.1038/nature17147

Lunar true polar wander inferred from polar hydrogen p.480

Polar hydrogen deposits on the Moon provide evidence that its spin axis has shifted; analysis of the locations of these deposits and of the lunar figure suggests that the shift occurred as a result of changes in the Moon’s moments of inertia caused by a low-density thermal anomaly beneath the Procellarum region.

doi: 10.1038/nature17166

The past, present and future of African dust p.493

Variability in North African dust dispersal, which affects air quality and the amount of radiation reaching the ground, is captured by the wind patterns over the Sahara; climate models suggest a downward trend in dust concentration with increasing greenhouse gas emissions.

doi: 10.1038/nature17149

Intrinsic honesty and the prevalence of rule violations across societies p.496

To test whether there is a relationship between the level of national corruption and the intrinsic honesty of individuals, a behavioural test of the honesty of people from 23 countries was conducted; the authors found that high national scores on an index of rule-breaking are linked with reduced personal honesty.

doi: 10.1038/nature17160

Visualization of immediate immune responses to pioneer metastatic cells in the lung p.513

Tracing the fate of circulating tumour cells by intravital two-photon lung imaging shows that tumours produce microparticles as they arrive and these migrate along the lung vasculature and are mostly taken up by interstitial myeloid cells, in a process that contributes to metastatic seeding; a minor subset of microparticles is engulfed by conventional dendritic cells, which are thought to contribute to the initiation of an anti-tumour immune response in lung-draining lymph nodes.

doi: 10.1038/nature16985

Melanoma addiction to the long non-coding RNA SAMMSON p.518

A known oncogene, MITF, resides in a region of chromosome 3 that is amplified in melanomas and associated with poor prognosis; now, a long non-coding RNA gene, SAMMSON, is shown to also lie in this region, to also act as a melanoma-specific survival oncogene, and to be a promising therapeutic target for anti-melanoma therapy.

doi: 10.1038/nature17161

PGC1α drives NAD biosynthesis linking oxidative metabolism to renal protection p.528

The energetic burden of continuously concentrating solutes against gradients along the tubule may render the kidney especially vulnerable to ischaemia. Acute kidney injury (AKI) affects 3% of all hospitalized patients. Here we show that the mitochondrial biogenesis regulator, PGC1α, is a pivotal determinant of renal recovery from injury by regulating nicotinamide adenine dinucleotide (NAD) biosynthesis. Following renal ischaemia, Pgc1α−/− (also known as Ppargc1a−/−) mice develop local deficiency of the NAD precursor niacinamide (NAM, also known as nicotinamide), marked fat accumulation, and failure to re-establish normal function. Notably, exogenous NAM improves local NAD levels, fat accumulation, and renal function in post-ischaemic Pgc1α−/− mice. Inducible tubular transgenic mice (iNephPGC1α) recapitulate the effects of NAM supplementation, including more local NAD and less fat accumulation with better renal function after ischaemia. PGC1α coordinately upregulates the enzymes that synthesize NAD de novo from amino acids whereas PGC1α deficiency or AKI attenuates the de novo pathway. NAM enhances NAD via the enzyme NAMPT and augments production of the fat breakdown product β-hydroxybutyrate, leading to increased production of prostaglandin PGE2 (ref. 5), a secreted autacoid that maintains renal function. NAM treatment reverses established ischaemic AKI and also prevented AKI in an unrelated toxic model. Inhibition of β-hydroxybutyrate signalling or prostaglandin production similarly abolishes PGC1α-dependent renoprotection. Given the importance of mitochondrial health in ageing and the function of metabolically active organs, the results implicate NAM and NAD as key effectors for achieving PGC1α-dependent stress resistance.

doi: 10.1038/nature17184