Volume 525 Number 7567

Editorials

Personal responsibility p.5

The US Precision Medicine Initiative needs to tread carefully when revealing health and genetic data to participants.

doi: 10.1038/525005a

News

News Features

News & Views

Problems at the nuclear pore p.36

Expansion of a repetitive DNA sequence is associated with neurodegeneration. Three studies identify genes involved in nuclear import and export that can mediate the toxicity this expansion causes. See Article p.56 & Letter p.129

doi: 10.1038/nature15208

Frictionless fluids from bacterial teamwork p.37

By increasing the sensitivity of an established technique, researchers have shown that swimming bacteria can make frictionless fluids — with potential applications in areas such as microfluidics.

doi: 10.1038/525037a

Global trends in plant naturalization p.39

Many naturalized non-native plants pose ecological and economic threats. A quantitative analysis of the global distribution of naturalized plants confirms some anticipated trends and exposes new patterns. See Letter p.100

doi: 10.1038/nature15206

Extraordinarily conventional p.40

Attitudes to high-temperature superconductivity have swung from disbelief to a conviction that it occurs only 'unconventionally'. But conventional superconductivity is now reported at record high temperatures. See Letter p.73

doi: 10.1038/nature15203

Location affects sporulation p.42

Monitored changes in the number of copies of a gene during DNA replication control the timing of sporulation in bacteria. This discovery links replication to the concept that a gene's location on a chromosome can influence cell traits.

doi: 10.1038/nature15207

The diversified economics of soil water p.43

Soil water that evaporates or is tapped by plants is largely separate from that which runs into streams and recharges groundwater. This finding has big implications for our understanding of water cycling. See Letter p.91

doi: 10.1038/525043a

Unequal opportunity during class switching p.44

The DNA breakage-and-repair mechanism that generates antibodies of different classes has, in theory, a 50% chance of occurring correctly. But this recombination turns out to be heavily biased towards productive events. See Letter p.134

doi: 10.1038/nature15209

Review

The quiet revolution of numerical weather prediction p.47

The cumulative progress of numerical weather prediction represents one of the most remarkable successes of modern science; here the many technological and scientific advances that have brought NWP to its present level are reviewed, as are the considerable challenges for the future.

doi: 10.1038/nature14956

Articles

Letters

Negative refractive index and acoustic superlens from multiple scattering in single negative metamaterials p.77

A negative refractive index, a property that does not exist in natural materials, can be produced in so-called metamaterials by combining two building blocks; here it is shown that it is possible to design and fabricate a metamaterial with a negative refractive index that consists of only one type of building block by taking advantage of its crystalline structure, and this approach is demonstrated through an acoustic superlens.

doi: 10.1038/nature14678

Guiding the folding pathway of DNA origami p.82

Probing the assembly process that occurs when single-stranded DNA is folded into desired shapes by ‘DNA origami’ shows that it can be guided by controlling the strengths of local and long-range interactions, enabling more reproducible synthesis.

doi: 10.1038/nature14860

Alcohols as alkylating agents in heteroarene C–H functionalization p.87

The biochemical process of spin-centre shift is used to accomplish mild, non-traditional alkylation reactions using alcohols as radical precursors; this represents the first broadly applicable use of unactivated alcohols as latent alkylating reagents, achieved via the successful merger of photoredox and hydrogen atom transfer catalysis.

doi: 10.1038/nature14885

Global separation of plant transpiration from groundwater and streamflow p.91

Soil water is usually assumed to be equally available for all purposes, supplying plant transpiration as well as groundwater and streamflow; however, a study of hydrogen and oxygen isotopes from 47 globally distributed sites shows that in fact the water used by plants tends to be isotopically distinct from the water that feeds streamflow.

doi: 10.1038/nature14983

Broad plumes rooted at the base of the Earth's mantle beneath major hotspots p.95

Plumes of hot upwelling rock rooted in the deep mantle have been proposed as a possible origin of hotspot volcanoes, but this idea is the subject of vigorous debate. On the basis of geodynamic computations, plumes of purely thermal origin should comprise thin tails, only several hundred kilometres wide, and be difficult to detect using standard seismic tomography techniques. Here we describe the use of a whole-mantle seismic imaging technique—combining accurate wavefield computations with information contained in whole seismic waveforms—that reveals the presence of broad (not thin), quasi-vertical conduits beneath many prominent hotspots. These conduits extend from the core–mantle boundary to about 1,000 kilometres below Earth’s surface, where some are deflected horizontally, as though entrained into more vigorous upper-mantle circulation. At the base of the mantle, these conduits are rooted in patches of greatly reduced shear velocity that, in the case of Hawaii, Iceland and Samoa, correspond to the locations of known large ultralow-velocity zones. This correspondence clearly establishes a continuous connection between such zones and mantle plumes. We also show that the imaged conduits are robustly broader than classical thermal plume tails, suggesting that they are long-lived, and may have a thermochemical origin. Their vertical orientation suggests very sluggish background circulation below depths of 1,000 kilometres. Our results should provide constraints on studies of viscosity layering of Earth’s mantle and guide further research into thermochemical convection.

doi: 10.1038/nature14876

Genetic evidence for two founding populations of the Americas p.104

Previous genetic studies have suggested that the Americas were peopled by a single founding population of Eurasian origin, but a genome-wide study of 30 Native American groups shows that Amazonian Native Americans also have a second source of ancestry that is deeply related to indigenous Australians, New Guineans and Andaman Islanders.

doi: 10.1038/nature14895

Mutations in DCHS1 cause mitral valve prolapse p.109

Two mutations in the gene DCHS1 are shown to cause non-syndromic mitral valve prolapse (MVP), a common cardiac valve disease; understanding the role of DCHS1 in mitral valve development and MVP pathogenesis holds therapeutic potential.

doi: 10.1038/nature14670

PIK3CAH1047R induces multipotency and multi-lineage mammary tumours p.114

The adult mouse mammary epithelium contains self-sustained cell lineages that form the inner luminal and outer basal cell layers, with stem and progenitor cells contributing to its proliferative and regenerative potential. A key issue in breast cancer biology is the effect of genomic lesions in specific mammary cell lineages on tumour heterogeneity and progression. The impact of transforming events on fate conversion in cancer cells of origin and thus their contribution to tumour heterogeneity remains largely elusive. Using in situ genetic lineage tracing and limiting dilution transplantation, we have unravelled the potential of PIK3CAH1047R, one of the most frequent mutations occurring in human breast cancer, to induce multipotency during tumorigenesis in the mammary gland. Here we show that expression of PIK3CAH1047R in lineage-committed basal Lgr5-positive and luminal keratin-8-positive cells of the adult mouse mammary gland evokes cell dedifferentiation into a multipotent stem-like state, suggesting this to be a mechanism involved in the formation of heterogeneous, multi-lineage mammary tumours. Moreover, we show that the tumour cell of origin influences the frequency of malignant mammary tumours. Our results define a key effect of PIK3CAH1047R on mammary cell fate in the pre-neoplastic mammary gland and show that the cell of origin of PIK3CAH1047R tumours dictates their malignancy, thus revealing a mechanism underlying tumour heterogeneity and aggressiveness.

doi: 10.1038/nature14669

GGGGCC repeat expansion in C9orf72 compromises nucleocytoplasmic transport p.129

An unbiased genetic screen in Drosophila expressing G4C2-repeat-containing transcripts (repeats that in human cause pathogenesis in C9orf72-related neurological disease) finds genes that encode components of the nuclear pore and nucleocytoplasmic transport machinery, and reveals that G4C2 expanded-repeat-induced alterations in nucleocytoplasmic transport contribute to C9orf72 pathology and neurodegeneration.

doi: 10.1038/nature14974