An international team led by investigators at Princeton University shows in a paper published online in advance in Nature this week that "the evolution of naked cuticle on larvae of Drosophila sechellia resulted from changes in five transcriptional enhancers of shavenbaby." With a functional assay, the researchers quantified the consequences of nucleotide substitutions on D. sechellia larval morphology, finding that each "had a relatively small phenotypic effect, and that many nucleotide changes account for this large morphological difference."
In another Nature advance online publication, researchers at the Israel Institute of Technology and elsewhere report their use of both whole-genome sequencing and a PCR screening technique to "investigate the effect of resistance on genome evolution and the genomic mechanisms behind the long-term coexistence of Prochlorococcus and their viruses." In analyzing 77 sub-strains selected for resistance to 10 viruses, the team found that "mutant genes are generally uncommon in nature," and further, that "viral-attachment genes are preferentially located in genomic islands and that viruses are a selective pressure enhancing the diversity of both island genes and island gene content," the authors write.
Members of The Cancer Genome Atlas Research Network this week present "integrated genomic analyses of ovarian carcinoma." The researchers show that "high-grade serous ovarian cancer is characterized by TP53 mutations in almost all tumors." The team proposes "four ovarian cancer transcriptional subtypes, three microRNA subtypes, four promoter methylation subtypes" and reports its identification of a "transcriptional signature associated with survival duration." Our sister publication GenomeWeb Daily News has more on this study.
The Children's Hospital of Philadelphia's Hojun Li et al. show in a paper published online in advance this week that zinc-finger nucleases are not only able to efficiently induce double-strand breaks "when delivered directly to mouse liver," but also that, "when co-delivered with an appropriately designed gene-targeting vector, they can stimulate gene replacement through both homology-directed and homology-independent targeted gene insertion at the ZFN [zinc-finger nucleus]-specified locus." Further, CHOP's Li and colleagues demonstrate that the level of gene-targeting they were able to achieve using ZFNs is "sufficient to correct the prolonged clotting times in a mouse model of hemophilia B."