In Nature this week, a team of US and Swedish researchers reports on the identification of a transcription factor that contributes to the beak diversity that Charles Darwin identified among Galapagos finches. The researchers performed whole-genome re-sequencing on 120 Galapagos finches spanning 15 species. They found that variants of the ALX1 gene are strongly associated with beak variation among all species examined, as well as with the rapid evolutionary change in beak size of one particular species. Notably, the same gene is involved in the development of the face and skull in humans. GenomeWeb has more on this here.
Meanwhile, in Nature Methods, a South Korean research team presents details of a new method for the genome-wide profiling of off-target effects of CRISPR/Cas9 gene editing in human cells. Called Digenome-seq, the approach involves digesting human genomic DNA with Cas9 in vitro, followed by whole-genome sequencing. The digest yields sequence reads with the same 5' ends at cleavage sites that can be computationally identified. Using the method, they were able to validate off-target sites at which insertions or deletions occurred with frequencies near the detection limit of targeted deep sequencing. The scientists also demonstrated that Cas9 off-target effects could be avoided by using modified guide RNAs to direct Cas9.