Editor's Note: Some of the articles described below are not yet available at the PNAS site, but they are scheduled to be posted some time this week.
In the early, online edition of the Proceedings of the National Academy of Sciences, an international research team took a look at ancestry and admixture patterns in three populations from Brazil. The researchers genotyped almost 6,500 individuals from sites in the country's northeast, southeast, and south, teasing apart African, European, and Native American ancestry tracts in individuals from each site. Together with genome sequence data on 30 Brazilians from these populations, the genotypes provided a look at mating patterns, past migration events, and more. GenomeWeb has more on the study, here.
An Imperial College London team describes a new double-stranded RNA mycovirus that it detected inside the pathogenic fungus Aspergillus fumigatus. The researchers caught wind of the virus — dubbed Aspergillus fumigatus tetramycovirus-1, or AfuTmV-1 — when they screened hundreds of A. fumigatus isolates for RNA viruses. Along with chrysovirus and partitivirus representatives, the team found a previously undescribed mycovirus with a genome comprised of four different double-stranded RNAs. The team went on to characterize the virus further, demonstrating that both the purified virus and its naked RNA can infect fungal protoplasts.
Finally, Ohio State University's Carlo Croce and colleagues present evidence suggesting the microRNA miR-148a can bump up non-small cell lung cancer response to treatment with the "TNF-related apoptosis-inducing ligand," or TRAIL. Using quantitative real-time PCR, the researchers compared miRNA expression patterns in TRAIL-susceptible and -resistant lung cell lines exposed to ever more TRAIL. Their results pointed to declining miR-148a expression with growing TRAIL-resistance — a shift that they subsequently showed was linked to enhanced NSCLC tumorigenesis in vitro and in vivo. On the other hand, dialing up levels of the miRNA seemed to sensitize cells to the treatment and curb this tumorigenesis by mediating activity of at least two enzyme-coding genes.