Scientists at the Oregon Health and Science University show in work published in the early online edition of Nature this week that they can replace a diseased mitochondrial genome in egg cells. Using a technique called spindle-chromosomal complex transfer, they transferred the mitochondrial genome from a mature Macaca mulatta egg cell into another egg cell that had a nucleus but no mitochondrial genome. From these, they were able to give birth to healthy monkeys. The technique could be used to prevent diseases caused by mutation in mitochondrial DNA, says a BBC story.
A news story reports that FDA has changed the labeling of two prominent cancer drugs. Upon evaluating data from several clinical trials, last month FDA’s Oncologic Drugs Advisory Committee recommended that the drugs Erbitux and Vectibix, for patients with advanced-stage colorectal cancer, should now be prescribed only to individuals with a non-mutated K-RAS gene.
Scientists led by the Salk Institute’s Fred Gage have studied how long interspersed element 1 retrotransposons affect brain cells. Their study demonstrates that neural progenitor cells "support the retrotransposition of engineered human L1s in vitro." Using qPCR, they found an increase in the copy number of L1s in the hippocampus, as compared to heart and liver, suggesting that "de novo L1 retrotransposition events may occur in the human brain and, in principle, have the potential to contribute to individual somatic mosaicism,” they say. A News and Views article has more.
And in Nature Biotechnology, a study led in part by Sanford Markowitz at Case Western Reserve University created a new technique to digitally count DNA methylation marks. Using methylated vimentin as a biomarker in plasma samples, their methyl-BEAMing method detected 59 percent of cancer cases, and it found as few as one methylated molecule in approximately 5,000 unmethylated molecules in DNA from plasma or fecal samples.