Volume 468 Issue 7325, 9 December 2010

Germany must better explain the scientific use of animals to remain a major biomedical force.

Funding agencies should make researchers reveal industry links.

Female researchers still battle sexism. The media gives them an opportunity to be heard alongside male colleagues, says Jennifer Rohn

The week in science.

Pacific nations to restrict fishing across a vast swathe of international waters.

Researchers question the science behind last week's revelation of arsenic-based life.

Dialogue with public is key to reducing opposition over the use of lab animals.

Nobel laureate to test link between autism and infection.

Plan to save Australian river system runs aground.

Technology is bringing down instances of duplication, despite variability in oversight.

Replacing genes with drugs could allow safe reprogramming.

John Reppy has come out of retirement to question the high-profile discovery of a new kind of quantum matter.

Researchers are sure that they can put lab-grown meat on the menu — if they can just get cultured muscle cells to bulk up.

Developing countries wanting to boost commercialization of their academic research should learn from the mistakes of US patenting legislation, says Bhaven N. Sampat.

Funders and universities should make the products of research more available — even if today's researchers pay a price, say Jeffrey L. Furman, Fiona Murray and Scott Stern.

An engaging biography of John Atanasoff reveals the obscure origins of the computer, explains John Gilbey.

Neil Dodgson admires the technical mastery of sculptor Anish Kapoor.

A useful guide to citation analysis shows that counting publications is harder than it looks, finds Ton van Raan.

Prince Charles's call to stay close to nature follows a rich tradition of environmental thinking, says Philip Stott.

Physicist who helped to unravel the mysteries of superconductivity.

Comparative genomics studies reveal molecular signatures of the controversial 'phylotypic' stage — a time when embryos of members of an animal phylum all look more alike than at other embryonic stages. See Letters p.811 & p.815

Quantum entanglement has been observed at low temperatures in both microscopic and macroscopic systems. It now seems that the effect can also occur at high temperatures if the systems are not in thermal equilibrium.

Tumour stem cells are proposed to be the source of tumour cells. It now emerges that they also give rise to the endothelial cells that line the tumour vasculature, mediating tumour growth and metastasis. See Letters p.824 & p.829

When and how the first stars and galaxies ionized the primordial hydrogen atoms that filled the early Universe is not known. Observations with a single radio antenna are opening a new window on the process. See Letter p.796

The Lassa virus nucleoprotein coats the viral genome to make a template for RNA synthesis. A study shows that it also binds the 'cap' structure of cellular messenger RNAs and directs immune evasion using a novel mechanism. See Article p.779

New astronomical and laboratory data show that the abundances of the two dominant ices, nitrogen and methane, on the surfaces of the Solar System's two largest dwarf planets are surprisingly similar — raising fresh questions.

Sliding of the Greenland ice sheet is affected by the production of surface meltwater. A new theory shows that whether the result is a long-term speed-up or slow-down of ice motion depends on the variability in melt input. See Letter p.803

The first crystal structure for an arenavirus nucleoprotein is solved, revealing some new functions. The C-terminal domain has 3′ to 5′ exonuclease activity, and it is confirmed that Lassa virus nucleoprotein is capable of cleaving short RNAs and suppressing virus-induced interferon induction. The N-terminal domain contains a unique cap-binding feature, which has implications for understanding the distinctive cap-snatching mechanism of arenaviruses.

tRNAs are synthesized in a premature form that requires trimming of the 5′ and 3′ ends and modification of specific nucleotides. RNase P, a complex containing a long catalytic RNA and a protein cofactor, catalyses the cleavage that generates the mature 5′ end. Here, the structure of RNase P bound to mature tRNA^Phe is solved. Recognition of the leader sequence and its mechanism of cleavage is determined by soaking an oligonucleotide corresponding to the premature 5′ end into the crystal.

Cysteine is the most intrinsically nucleophilic amino acid in proteins, but the absence of a consensus sequence that defines functional cysteines in proteins has hindered their discovery and characterization. Here, a proteomics method to quantitatively profile the intrinsic reactivity of cysteine residues directly in native biological systems is described. Hyper-reactive cysteines were identified in several proteins of uncharacterized function, including a residue conserved across eukaryotes that is shown to be required for yeast viability and involved in iron–sulphur protein biogenesis.

Observations of the 21-centimetre line of atomic hydrogen in the early Universe directly probe the history of the reionization of the gas between galaxies. If reionization happened rapidly, there will be a characteristic signature visible against the smooth foreground in an all-sky spectrum. Here, an all-sky average spectrum between 100 and 200 MHz is reported, corresponding to the redshift range 6 < z < 13 for the 21-centimetree line. The data exclude a rapid reionization timescale of Δz < 0.06 at the 95% confidence level.

The development of table-top femtosecond electron diffraction sources in recent years has opened up a new way to observe atomic motions in crystalline materials undergoing structural changes. Here, the technique is used to study the charge density wave material 1T-TaS₂, where a modulation of the electron density is accompanied by a periodic lattice distortion. In this femtosecond electron diffraction experiment, where atomic motions are observed in response to a 140 femtosecond optical pulse, the periodic lattice distortion is found to collapse on an exceptionally fast timescale (about 250 femtoseconds), indicative of an electronically driven process involving a highly cooperative process.

Increased melting is often assumed to cause acceleration of ice sheets and glaciers through basal lubrication, possibly leading to increased rates of sea level rise. Now a physically-based model challenges this view, illustrating that above a critical threshold, increased melt will suppress the dynamic thinning process. Short-term spikes in water delivery, as from lake drainage or precipitation, still have the potential to generate spikes in velocity, but overall increases in melt do not appear likely to cause velocity increases.

For two hundred years, scientists have noticed that the appearance of embryos in related species converge in their appearance mid-way in development, diverging thereafter. But is this 'phylotypic stage' real, and how is it connected with the genetic basis of development? Here, a method linking the genes transcribed at various stages of development (the transcriptome) with the evolutionary history of those genes is used. Genes transcribed in the phylotypic stage are, in evolutionary terms, the oldest and most conserved. This suggests that the phylotypic stage does represent the body plans of related species at their most unadorned, selection having sculpted the earlier and later stages of embryonic form to suit the particulars of each creature.

For two hundred years, scientists have noticed that the appearance of embryos in related species converge in their appearance mid-way in development, diverging thereafter. But is this 'phylotypic stage' real, and how is it connected with the genetic basis of development? This issue is looked at in microcosm, concentrating on gene expression during the development of six species of the fruitfly Drosophila. It is shown that the genes expressed during the phylotypic stage are more conserved across the genus, supporting the age-old model.

In his study of Brownian motion, Einstein realized that the same random molecular movements characterizing a substance at rest should affect, for example, the drag it opposes to a particle pushed through it. This was later generalized as the fluctuation–response theorem (FRT), but whether and how it may apply to biological systems, which operate far from equilibrium, has remained an open question. Based on the unmatched fine-scale measurements possible in the study of bacterial chemotaxis, it is now revealed that the FRT does apply in this case, and ways to dissect which features in the biochemical network couple its internal states with its responses to external stimuli are suggested.

This is one of two papers showing that glioblastoma cells can differentiate into functional endothelial cells as part of the tumour vasculature. These endothelial cells are characterized by the same genetic alterations as the glioblastoma cells. The tumour-derived endothelial cells originate in putative glioblastoma-initiating cells and are functionally important for tumorigenesis.

This is one of two papers showing that glioblastoma cells can differentiate into functional endothelial cells as part of the tumour vasculature. These endothelial cells are characterized by the same genetic alterations as the glioblastoma cells. The tumour-derived endothelial cells originate in putative glioblastoma-initiating cells and are functionally important for tumorigenesis.

Lipid asymmetry can be disrupted during biological processes such as apoptosis, during which phosphatidylserine in the inner leaflet of the membrane is exposed on the outer membrane. It has been proposed that activation of a phospholipid scramblase catalyses bidirectional transbilayer movement of phospholipids, but the protein corresponding to this activity has not been identified. Here, the protein TMEM16F is identified, and is an essential component for the Ca²⁺-dependent exposure of phosphatidylserine on the plasma membrane. A patient with Scott syndrome, which results from a defect in phospholipid scrambling activity, was found to carry a mutation in the gene encoding TMEM16F.

The TET family of enzymes convert 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) in DNA. Mutations in the gene encoding TET2 are frequently observed in myeloid malignancies. Here it is shown that these disease-associated mutations compromise TET2 catalytic activity; bone marrow samples from patients with TET2 mutations have low levels of 5hmC in genomic DNA, and TET2 is required for normal haematopoietic differentiation. Measurement of genomic 5hmC levels may prove valuable as a diagnostic tool in myeloid cancers.

Channels and transporters in the ClC family are homodimeric; however, the aqueous pores for anion diffusion in the channels and the ion-coupling chambers that coordinate Cl⁻ and H⁺ antiport in the transporters are contained wholly within each subunit of the homodimer. Here mutations in a Cl⁻/H⁺ exchanger were made that destabilized the dimer interface; the resulting mutant channel is monomeric, yet it is functionally nearly identical to the wild-type channel. This means that cross-subunit interaction is not required for Cl⁻/H⁺ exchange in ClC transporters, which raises the question: why is the wild-type transporter a homodimer?

Developing techniques are helping researchers to build the protein interaction networks that underlie all cell functions.

Disease outbreaks in recent years have revealed the vulnerability of food supplies. But they offer opportunities for those interested in waging war on microbes.

Rutgers University biophysicist explains how heading overseas has enriched his career.

UK granting agencies aim for greater impact.

Irish partnership gets €19-million government grant for diagnostics R&D.

Acting on council's recommendations would mean more jobs and funds for young researchers in Europe.

Problem solved.