Investigators at Stockholm University and their colleagues show in a Genome Research paper published online in advance this week that adenosine to inosine editing of miRNAs increases in the mouse brain during development, and that it "gradually changes the proportions of the two miR-376a isoforms." Further, "by comparing editing of pre-miRNA with editing and expression of the corresponding mature miRNA, we also show an editing induced developmental regulation of miRNA expression," the authors report.
In another advance online article, Emory University's Michael Zwick and his colleagues present the evolution of Bacillus anthracis in the context of Bacillus cereus sensu lato species' genomes. From sequences for 45 strains of the B. cereus sensu lato group, the team says it "called more than 324,000 new genes representing more than 12,333 new gene families for this group," adding that the species' core genome size is approximately 1,750 genes, "with another 2,150 genes found in almost every genome constituting the extended core." Overall, Zwick and his colleagues say that "although B. anthracis has undergone an ecological shift within the species, its chromosome does not appear to be exceptional on a macroscopic scale compared to close relatives."
Elsewhere in Genome Research, a team led by researchers at Stanford University presents evidence to suggest that "cis-regulatory adaptation can occur at the level of physically interacting modules, and that one such polygenic adaptation led to increased virulence during the evolution of a pathogenic yeast."