A gap-free rye genome, a giant caiman relative and a lead-free ammonia sensor
A gap-free rye genome assembly exposes new genetic diversity for wheat breeding. Elsewhere, bite marks placed a giant caiman relative at the top of Miocene Colombia's food chain, and a lead-free perovskite film detected ammonia in 13 seconds.
Science··Morning
A gap-free rye genome exposes new genetic diversity for wheat breeding
An international team at the Leibniz Institute of Plant Genetics and Crop Plant Research assembled the rye line Lo7 with long-read sequencing, resolving complete centromere sequences for all seven chromosome pairs. This closes gaps left in a 2021 assembly of rye's large genome, which is roughly 90 percent repetitive. Published in Nature Communications, the work targets the 1RS chromosome arm, which is already used in wheat breeding for disease resistance and vigour. The new assembly shows the 1RS arm varies more across rye genotypes than the segments current wheat programmes use. The paper reports genomic diversity rather than a measured yield gain in the field.[1]
Bite marks put a giant caiman relative at the top of Miocene Colombia's food chain
Oscar Wilson and colleagues at the University of Helsinki examined bones between 10.5 and 16 million years old from Colombia's Middle Miocene and found feeding marks they attribute to Purussaurus neivensis, a crocodylian that reached about 7 metres in length and 1,800 kilograms in mass. Published in the Journal of Vertebrate Paleontology, the frequency of these marks points to crocodylians rather than mammalian predators as the main consumers of large herbivores in that ecosystem. Because scavenging leaves similar traces, a bite mark records an interaction rather than establishing a kill, so the authors' claim concerns what was eating large herbivores rather than how they died.[2]
A lead-free perovskite sensor detects ammonia in 13 seconds in the laboratory
Researchers at the Korea Institute of Materials Science developed a thin film from formamidinium antimony bromide that detects ammonia down to 1 ppm and responds within 13 seconds at 100 ppm. The sensor's response to methane, carbon monoxide, nitrogen oxides, hydrogen, and methanol was substantially smaller. Published in Small Structures, the novelty lies in the mechanism: rather than relying on surface adsorption like earlier sensors, ammonia molecules slot reversibly into the perovskite lattice and dope it p-type, raising its conductivity. The film held about 97 percent of its performance after two months, remaining a laboratory demonstration rather than a deployed leak detector.[3]
