In Nature Biotechnology this week, a team led by Massachusetts Institute of Technology researchers report on the use of a gene-editing approach called CRISPR to correct a disease mutation and phenotype in mice, furthering the therapeutic potential of the technology. In the study, the scientists were able to deliver into the animals the Cas9 nuclease, along with a snippet of RNA that directed the enzyme to a specific portion of DNA where it causes double-strand breaks. In doing so, they were able to prevent expression of a mutant gene that causes the accumulation of toxic metabolites, while increasing the expression of the wild-type gene and reversing the body weight loss that characterizes the disease.
Meanwhile, in Nature Methods, another group from MIT presents details of a novel quantitative technique for sorting cells by endogenous RNA abundance. The investigators show how the method can be used to extract RNA from transcriptionally sorted cells efficiently and in an unbiased manner, and report a high-fidelity transcriptome measurement of mouse induced pluripotent stem cells isolated from a heterogeneous reprogramming culture.
Genetic variants common between modern humans and Neanderthals, but lacking in chimpanzees are enriched in lipid metabolism genes in people of European, but not East Asian descent, researchers from the CAS-MPG Partner Institute for Computational Biology in Shanghai and elsewhere report in Nature Communications. They scoured the genomes of 11 modern human populations, looking for regional similarities to the Neanderthal genome, and found that lipid catabolism genes in modern Europeans were similar to those of Neanderthals. Additionally, they found indications of positive selection associated with those regions. "Functionally, the excess of Neanderthal-like sites in lipid catabolism genes can be linked with a greater divergence of lipid concentrations and enzyme expression levels within this pathway, seen in contemporary Europeans, but not in the other populations," the researchers add. 'We conclude that sequence variants that evolved in Neanderthals may have given a selective advantage to anatomically modern humans that settled in the same geographical areas."