In PLOS Genetics, Washington State University researchers report on a role for nucleosome structure in ultraviolet light-induced mutational signatures in melanoma. Using a combination of sequencing approaches, the team profiled UV-induced cyclobutane pyrimidine dimer (CPD) mutation patterns and tracked nucleosome positions in almost 200 cutaneous melanoma cases, uncovering mutation density oscillations that appeared to coincide with nucleosome placement. These mutation undulations turned up in a range of chromatin, histone, and transcription contexts, the authors note, though muted transcription tended to coincide with a rise in the density of the mutations.
A team from Japan and Nigeria explore genetic features and phylogenetic relationships between Lassa virus (LASV) strains involved in Lassa fever cases at hospitals in southern Nigeria between 2012 and 2016 for a paper in PLOS Neglected Tropical Diseases. After finding 29 LASV-positive samples from 123 potential Lassa fever cases, the researchers sequenced genes in 11 LASV isolates and used profiles for four genes to tease apart phylogenetic relationships between them. In the process, they saw two phylogenetic clades that appear to have been evolving independently since splitting from a shared common ancestor almost 200 years ago. The authors say the findings "have important implications for vaccine development, diagnostic assay design, and [Lassa fever] outbreak management."
Russian researchers profile genetic diversity and population structure in reindeer (Rangifer tarandus) — including wild populations in the Taymyr Peninsula and Sakha Republic — for a study published in PLOS One. The team relied on an Illumina bovine BeadChip array to assess genome-wide SNP profiles in 61 wild and 74 domestic reindeer from taiga boreal forest, tundra, or farm populations, using insights from almost 8,400 polymorphic markers to detect define population structures and define genetic differences between wild and domestic reindeer. Along with enhanced genetic diversity in the wild populations, for example, the results pointed to genetic clustering that roughly corresponded to geographic region in the domestic populations.