By sequencing the genomes of 11 individuals with a severe form of childhood amyotrophic lateral sclerosis (ALS), a team led by National Institutes of Health researchers has identified a set of rare mutations that cause the disease. In these patients, they discovered variants in the gene SPTLC1, which is involved in lipid metabolism, and found that these mutations disrupt the production of an enzyme called serine palmitoyltransferase (SPT), leading to unrestrained sphingolipid production and accumulation in the motor neurons affected in ALS. "Alterations in SPT activity have been linked to neurodegeneration, the study's authors write this week in Nature Medicine. "Nevertheless, no human disease has been linked to SPT overactivity." The study's authors also developed small interfering RNAs that target the ALS-causing SPTLC1 allele for degradation while leaving the normal allele intact and normalize sphingolipid levels in vitro as a proof-of-concept for a precision medicine approach for treating this form of ALS.
Genetic variation is commonly used to improve crop yield and quality, but hexaploid wheat — one of the world's most important crop plants — remains intractable to selective breeding given the narrow diversity of its genome. To address this, a group led by Henan University scientists developed an approach that takes advantage of the genomic variations in the grass species Aegilops tauschii. As described in Nature Plants last week, they developed a platform to rapidly introduce genetic variations from A. tauschii into wheat through a combination of introgression technology, speed breeding, and high-throughput genotyping and phenotyping. The investigators assembled four new reference genomes and resequenced 278 accessions of A. tauschii, revealing "extensive untapped variations" in the plant and introduce improvements in preharvest sprouting resistance and grain weight of new wheat lines.