In a paper published online in advance in Science this week, researchers at the University of Virginia School of Medicine and the University of North Carolina at Chapel Hill, report on their identification of tens of thousands of "short extrachromosomal circular DNAs — microDNA — in mouse tissues as well as mouse and human cell lines." The team says these 200- to 400-base pair long microDNAs are "derived from unique nonrepetitive sequence, and are enriched in the 5' untranslated regions of genes, exons, and CpG islands." The team also shows that the generation of these extrachromosomal circular DNAs "leaves behind deletions in different genomic loci."
Over in this week's issue, investigators at Cornell University's Weill Medical College present "an approach for generating fluorescent sensors based on Spinach, an RNA sequence that binds and activates the fluorescence of a small-molecule fluorophore." The researchers say these Spinach-based sensors "can detect a variety of different small molecules in vitro and in living cells."
Researchers at the University of Illinois at Urbana-Champaign show that food-scouting honey bees show "extensive differences in brain gene expression relative to other foragers, including differences related to catecholamine, glutamate, and γ-aminobutyric acid signaling." Writing in Science this week, the team goes on to further explore the molecular underpinnings of scouting behavior in the bees.
Elsewhere in the issue, investigators at China's Sun Yat-sen University and their colleagues show that "nucleosome-dependent mutation spectra affect eukaryotic genome structure and evolution, and may have implications for understanding the origin of mutations in cancers and in induced pluripotent stem cells," and delve into "how the composition and structure of DNA within the cell affect spontaneous mutations."