Volume 515 Number 7525

Editorials

On the mend p.7

The scientific regeneration of central Europe is gathering pace, but needs further help to thrive.

doi: 10.1038/515007b

Protect the parks p.8

Balancing the needs of development and conservation is difficult — but urgent.

doi: 10.1038/515008a

News

Lobbying sways NIH grants p.19

Pressure on lawmakers from patient-advocacy groups has shaped agency spending on rare-disease research.

doi: 10.1038/515019a

News Features

Central Europe up close p.22

In the 25 years since the collapse of communism, the countries of central and Eastern Europe have each carved their own identity in science.

doi: 10.1038/515022a

News & Views

Surf's up at SLAC p.40

A 'plasma afterburner' just 30 centimetres long accelerates electrons hundreds of times faster than giant conventional accelerators. The result may ultimately open up a low-cost technology for particle colliders. See Letter p.92

doi: 10.1038/515040a

Cells unite by trapping a signal p.41

Gradients of fibroblast growth factors often induce cells to adopt different fates. A study in zebrafish embryos reveals another, unexpected role when the factors are trapped in small spaces by a special arrangement of cells. See Letter p.120

doi: 10.1038/nature13933

Monster star found hiding in plain sight p.42

Massive stars are rare, but they are sources of some of the most energetic phenomena seen in the Universe today. A high-mass candidate has now been found in a star-forming region that has been observed for more than 50 years.

doi: 10.1038/515042a

Diversity breeds complementarity p.44

Evolutionary and ecosystem processes have long been treated as distinct. The finding that interactions among plant species cause rapid evolutionary changes that affect ecosystem function suggests that it is time for unification. See Letter p.108

doi: 10.1038/nature13929

Shape control in reactions with light p.45

The report of a light-activated catalyst that dictates the three-dimensional shape — the stereochemistry — of molecules formed in an organic reaction suggests a new strategy for controlling such reactions using visible light. See Letter p.100

doi: 10.1038/515045a

Metastasis risk after anti-macrophage therapy p.46

Blocking the activity of macrophages may delay the spread of cancer. But new findings show that these immune cells can rapidly rebound to tumours after therapy withdrawal, accelerating lethal metastasis in mice. See Letter p.130

doi: 10.1038/nature13931

Articles

Life cycles, fitness decoupling and the evolution of multicellularity p.75

Simple cooperating groups of bacteria reproduced either by embracing or purging cheating types; those that embraced cheats adopted a life cycle of alternating phenotypic states, underpinned by a developmental switch that allowed the fitness of collectives to decouple from the fitness of constituent cells.

doi: 10.1038/nature13884

Architecture of mammalian respiratory complex I p.80

Complex I is the first enzyme of the mitochondrial electron transport chain and it is essential for oxidative phosphorylation in mammalian mitochondria; here the electron cryo-microscopy structure of complex I from bovine heart mitochondria is reported, advancing knowledge of its structure in mammals.

doi: 10.1038/nature13686

Letters

Suppression of cooling by strong magnetic fields in white dwarf stars p.88

Cool white dwarf stars often have mysteriously strong magnetic fields (because their coolness suggests that they are old, and magnetic fields should decline in strength with age) and unexplained brightness variations; here the magnetic field is shown to suppress atmospheric convection, inhibiting cooling evolution and causing dark spots.

doi: 10.1038/nature13836

Solution-processed, high-performance light-emitting diodes based on quantum dots p.96

The insertion of an insulating layer into a multilayer light-emitting diode (LED) based on quantum dots and produced by depositing the layers from solution increases the performance of the LEDs to levels comparable to those of state-of-the-art organic LEDs produced by vacuum deposition, while retaining the advantages of solution processing.

doi: 10.1038/nature13829

Asymmetric photoredox transition-metal catalysis activated by visible light p.100

A chiral iridium complex serves as a sensitizer for photoredox catalysis and at the same time provides very effective asymmetric induction for the enantioselective alkylation of 2-acyl imidazoles; the metal centre simultaneously serves as the exclusive source of chirality, the catalytically active Lewis acid centre, and the photoredox centre.

doi: 10.1038/nature13892

Nodal signalling determines biradial asymmetry in Hydra p.112

A Nodal-related gene is uncovered in Hydra and is involved in setting up the body axis, and a β-Catenin–Nodal–Pitx signalling cassette is shown to have existed before the divergence of cnidarians, including Hydra, and bilaterians.

doi: 10.1038/nature13666

Sensory-evoked LTP driven by dendritic plateau potentials in vivo p.116

Whole-cell recordings in mouse somatosensory cortex in vivo show that rhythmic sensory-whisker stimulation induces long-term synaptic potentiation (LTP) in layer 2/3 (L2/3) pyramidal cells, in the absence of somatic spikes, through long-lasting NMDAR-mediated depolarizations that are generated by synaptic networks originating from the posteromedial complex of the thalamus.

doi: 10.1038/nature13664

Tumour-infiltrating Gr-1+ myeloid cells antagonize senescence in cancer p.134

Aberrant activation of oncogenes or loss of tumour suppressor genes opposes malignant transformation by triggering a stable arrest in cell growth, which is termed cellular senescence. This process is finely tuned by both cell-autonomous and non-cell-autonomous mechanisms that regulate the entry of tumour cells to senescence. Whether tumour-infiltrating immune cells can oppose senescence is unknown. Here we show that at the onset of senescence, PTEN null prostate tumours in mice are massively infiltrated by a population of CD11b+Gr-1+ myeloid cells that protect a fraction of proliferating tumour cells from senescence, thus sustaining tumour growth. Mechanistically, we found that Gr-1+ cells antagonize senescence in a paracrine manner by interfering with the senescence-associated secretory phenotype of the tumour through the secretion of interleukin-1 receptor antagonist (IL-1RA). Strikingly, Pten-loss-induced cellular senescence was enhanced in vivo when Il1ra knockout myeloid cells were adoptively transferred to PTEN null mice. Therapeutically, docetaxel-induced senescence and efficacy were higher in PTEN null tumours when the percentage of tumour-infiltrating CD11b+Gr-1+ myeloid cells was reduced using an antagonist of CXC chemokine receptor 2 (CXCR2). Taken together, our findings identify a novel non-cell-autonomous network, established by innate immunity, that controls senescence evasion and chemoresistance. Targeting this network provides novel opportunities for cancer therapy.

doi: 10.1038/nature13638