In PLoS One this week, MIT researchers say they've developed the first ever broad-spectrum antiviral therapeutic. Instead of taking a pathogen-specific approach to developing antivirals, the team has created a new approach, called Double-Stranded RNA Activated Caspase Oligomerizer, or DRACO, which selectively induces apoptosis in cells that contain viral dsRNA, and kills infected cells without harming normal cells. "We have created DRACOs and shown that they are nontoxic in 11 mammalian cell types and effective against 15 different viruses, including dengue flavivirus, Amapari and Tacaribe arenaviruses, Guama bunyavirus, and H1N1 influenza," the team writes. "We have also demonstrated that DRACOs can rescue mice challenged with H1N1 influenza."
In PLoS Genetics this week, a team of researchers in North Carolina and Alabama says an analysis of DNA methylation in a three-generation family has revealed a widespread genetic influence on epigenetic regulation. The team applied reduced representation bisulfite sequencing to somatic DNA from six members of the subject family and observed that 8.1 percent of heterozygous SNPs are associated with differential methylation in cis. "The vast majority of differential methylation between homologous chromosomes (>92 percent) occurs on a particular haplotype as opposed to being associated with the gender of the parent of origin, indicating that genotype affects DNA methylation of far more loci than does gametic imprinting," the authors write. "We found that 75 percent of genotype-dependent differential methylation events in the family are also seen in unrelated individuals and that overall genotype can explain 80 percent of the variation in DNA methylation."
In PLoS Biology this week, researchers in New York and Utah suggest that Nemo-like kinases could have broader roles as regulators of cellular morphogenesis, in addition to their traditional role in regulating the Wnt signaling pathway. Despite the prevalence and importance of the "enclosed compartments" surrounding neuronal endings, not much is known about how they form, the authors write. Using the main sensory organ of C. elegans, the team found that daf-6/patched-related — a glia-expressed gene previously implicated in amphid sensory compartment morphogenesis — acts to restrict compartment size, and that the gene lit-1/Nemo-like kinase acts to counterbalance daf-6 and promote sensory compartment expansion. "Although LIT-1 has been shown to regulate Wnt signaling, our genetic studies demonstrate a novel, Wnt-independent role for LIT-1 in sensory compartment size control," the team writes. "The LIT-1 activator MOM-4/TAK1 is also important for compartment morphogenesis and both proteins line the glial sensory compartment. LIT-1 compartment localization is important for its function and requires neuronal signals."
And finally in PLoS One this week, a team of researchers from the J. Craig Venter Institute and the University of California, San Diego, present their characterization of the small RNA transcriptome of the Thalassiosira pseudonana diatom. The team constructed small RNA cDNA libraries for T. pseudonana and then subjected them to highly parallel pyrosequencing and sequence-by-ligation. "From the computational analysis of approximately 300,000 sequences in the 454 library and over 17 million sequences in the SOLiD libraries, there exists evidence of a core set of small RNA genes including: novel microRNAs, repeat-associated short interfering RNAs, and endogenous short interfering RNAs," the authors write. "The diatom genome contains elements similar to plant small RNA systems, such as the RNAi machinery, a high percentage of short interfering RNAs originating from protein-coding and repetitive regions of the genome, and putative binding sites of the small RNAs occurring primarily in the coding section of the predicted targets."