Volume 541 Number 7636

Editorials

Fantasy politics p.133

A US congressional investigation has distorted the truth about research that uses human fetal tissue — and sets a troubling precedent.

doi: 10.1038/541133a

News

News Features

News & Views

Stomach growth in a dish p.160

A protocol has been developed to grow structures that resemble the main part of the stomach in vitro from human embryonic stem cells — an advance that provides insights into stomach development. See Article p.182

doi: 10.1038/nature21110

Water flows out of touch p.161

Superhydrophobic surfaces reduce the frictional drag between water and solid materials, but this effect is often temporary. The realization of sustained drag reduction has applications for water vehicles and pipeline flows.

doi: 10.1038/541161a

Spot the difference p.162

A molecular analysis of human oesophageal cancers reveals abnormalities that might be targetable by existing drugs, and indicates that the current stratification of these tumours into subtypes is incomplete. See Article p.169

doi: 10.1038/nature21112

Supercavity lasing p.164

Light in a laser is confined in the form of standing waves. By engineering such waves, scientists have designed an optical system that enhances this confinement, producing a compact laser that emits a high-quality beam. See Letter p.196

doi: 10.1038/541164a

Mechanosensor of lung inflation identified p.165

The Piezo2 protein senses changes in lung volume, acting in different neurons to convey this information to the brain. This finding adds to the list of roles for Piezo2 in mechanosensation. See Article p.176

doi: 10.1038/nature21111

Valine starvation leads to a hungry niche p.166

The haematopoietic stem cells that rejuvenate blood depend on a dietary source of the amino acid valine — a finding that has been exploited to reduce the toxicity of bone-marrow transplantation in mice.

doi: 10.1038/nature21106

The resilience of Amazonian forests p.167

Isotope evidence suggests that, during dry periods associated with the most recent ice age, the Amazonian forest survived in a region that is sensitive to rainfall changes — settling a debate about Amazonian aridity. See Letter p.204

doi: 10.1038/541167a

Articles

Integrated genomic characterization of oesophageal carcinoma OPEN p.169

The Cancer Genome Atlas Research Network report integrated genomic and molecular analyses of 164 squamous cell carcinomas and adenocarcinomas of the oesophagus; they find genomic and molecular features that differentiate squamous and adenocarcinomas of the oesophagus, and strong similarities between oesophageal adenocarcinomas and the chromosomally unstable variant of gastric adenocarcinoma, suggesting that gastroesophageal adenocarcinoma is a single disease entity.

doi: 10.1038/nature20805

Letters

Structural variation in amyloid-β fibrils from Alzheimer's disease clinical subtypes p.217

Aggregation of amyloid-β peptides into fibrils or other self-assembled states is central to the pathogenesis of Alzheimer’s disease. Fibrils formed in vitro by 40- and 42-residue amyloid-β peptides (Aβ40 and Aβ42) are polymorphic, with variations in molecular structure that depend on fibril growth conditions. Recent experiments suggest that variations in amyloid-β fibril structure in vivo may correlate with variations in Alzheimer’s disease phenotype, in analogy to distinct prion strains that are associated with different clinical and pathological phenotypes. Here we investigate correlations between structural variation and Alzheimer’s disease phenotype using solid-state nuclear magnetic resonance (ssNMR) measurements on Aβ40 and Aβ42 fibrils prepared by seeded growth from extracts of Alzheimer’s disease brain cortex. We compared two atypical Alzheimer’s disease clinical subtypes—the rapidly progressive form (r-AD) and the posterior cortical atrophy variant (PCA-AD)—with a typical prolonged-duration form (t-AD). On the basis of ssNMR data from 37 cortical tissue samples from 18 individuals, we find that a single Aβ40 fibril structure is most abundant in samples from patients with t-AD and PCA-AD, whereas Aβ40 fibrils from r-AD samples exhibit a significantly greater proportion of additional structures. Data for Aβ42 fibrils indicate structural heterogeneity in most samples from all patient categories, with at least two prevalent structures. These results demonstrate the existence of a specific predominant Aβ40 fibril structure in t-AD and PCA-AD, suggest that r-AD may relate to additional fibril structures and indicate that there is a qualitative difference between Aβ40 and Aβ42 aggregates in the brain tissue of patients with Alzheimer’s disease.

doi: 10.1038/nature20814