News & Views
New research backs the contentious idea that solid tumours are not masses of equivalent cells, but instead contain cancer stem cells that support tumour maintenance. Here, two experts provide complementary views on the findings and on the implications for potential therapies. See Letters p.522 & p.527
A neat experiment shows that if a current is sent through one of two adjacent conducting layers placed in a strong magnetic field, a quantum effect generates an exactly equal but opposite current in the other layer. See Letter p.481
To understand how blood vessels form and function, scientists require reproducible systems that mimic living tissues. An innovative approach based on microfabricated vessels provides a key step towards this goal.
The identification of an enzyme in rice that confers improved plant yields on phosphorus-deficient soils could open up new avenues for generating nutrient-efficient crops that can thrive on marginally fertile soils. See Letter p.535
A comprehensive analysis of human spontaneous mutation has revealed a strong influence of paternal age, suggesting a link between an increasing number of older fathers and the rise in disorders such as autism. See Article p.471
A measurement by satellite altimetry shows the Himalayan glaciers to be losing mass at only moderate rates, but raises broader questions about other methods for estimating mass balance. See Letter p.495
Mutations generate sequence diversity and provide a substrate for selection. The rate of de novo mutations is therefore of major importance to evolution. Here we conduct a study of genome-wide mutation rates by sequencing the entire genomes of 78 Icelandic parent–offspring trios at high coverage. We show that in our samples, with an average father’s age of 29.7, the average de novo mutation rate is 1.20 × 10−8 per nucleotide per generation. Most notably, the diversity in mutation rate of single nucleotide polymorphisms is dominated by the age of the father at conception of the child. The effect is an increase of about two mutations per year. An exponential model estimates paternal mutations doubling every 16.5 years. After accounting for random Poisson variation, father’s age is estimated to explain nearly all of the remaining variation in the de novo mutation counts. These observations shed light on the importance of the father’s age on the risk of diseases such as schizophrenia and autism.