In PLOS Genetics, Colorado State University researchers report on results from a yeast genetic screen for sequences influencing yeast prion aggregation or degradation. Using randomly mutagenized yeast libraries missing the usual copy of a yeast prion protein called Sup35, the team searched for amino acid residues prompting the accumulation or breakdown of aggregation-prone, prion-like domain models from Sup35 and/or two human proteins. While some amino acids that support domain aggregation could also trigger domain degradation, depending on the nature of the specific prion domain features present, for example, others could not. "Our results highlight the complex interplay between pre-emptive protein degradation and protein aggregation, and implicate the unusual composition of yeast prion domains in preventing their degradation," the authors write.
A Pasteur Institute-led team takes a look at dengue virus genetic variation and its impact on transmission dynamics in the Aedes aegypti mosquito vectors for a paper in PLOS Pathogens. The researchers focused on eight field-derived dengue virus strains representing diversity documented around the world for the virus, following the time frames from virus acquisition to transmission in Ae. aegypti. With these data, they established simulation models suggesting the size and likelihood of dengue outbreaks in humans might hinge, in part, on these strain-dependent transmission patterns. "[O]ur results indicate that natural variation in mosquito infection dynamics between arbovirus strains may contribute to the unexplained heterogeneity of dengue virus transmission patterns," they note.
The gut microbial communities found in children or adolescents with attention deficit hyperactivity disorder (ADHD) may have diminished microbial diversity compared to gut microbiomes in unaffected control individuals, according to a PLOS One study by investigators from Germany. That team used 16S ribosomal RNA sequencing to profile gut microbe community membership in 14 males with ADHD and 17 unaffected male controls from the same age group. The analysis pointed to a dip in diversity and a distinct microbial makeup in the group of ADHD-affected children, including a rise in Neisseria and Prevotella species. "Taking the small sample size and concomitant medication into account," the researchers say, "our findings support the hypothesis of an ADHD-specific microbiota."