In a Science paper published online in advance this week, an international research team shows that blocking the expression of Xist, a non-coding RNA that inactivates one of the X chromosomes in females, improves somatic cell nuclear transfer in a mouse model. The team "also identified an Xist-independent mechanism that specifically down-regulated a subset of X-linked genes through somatic-type repressive histone blocks," it writes.
In another paper published online, a different international research team reports its detection of heterozygous germline mutations in IDH2 in patients with D-2-hydroxyglutaric aciduria, "a rare neurometabolic disorder characterized by supraphysiological levels of D-2-HG," it writes. The researchers also found that these mutations disable the normal enzymatic activity, but confer a new function — to convert 2-KG to D-2-hydroxyglutarate.
Researchers in France and Switzerland show in this week's Science that miR-16 targets SERT — the serotonin transporter — and is "expressed at higher levels in noradrenergic than in serotonergic cells." The team has found that mice treated with Prozac experience increases in miR-16 levels, which reduces SERT expression. The authors suggest that "miR-16 contributes to the therapeutic action of SSRI antidepressants in monoaminergic neurons."
And in Science Translational Medicine this week, an international research team led by investigators at the Johns Hopkins School of Medicine describe "personalized epigenomic signatures that are stable over time and covary with body mass index." Specifically, Andrew Feinberg et al. performed a genome-scale analysis of about four million CpG sites in 74 individuals and found "227 regions that showed extreme interindividual variability ... across the genome, which are enriched for developmental genes based on Gene Ontology analysis," they write. Variably methylated regions form a personalized epigenomic signature, the team postulates. They found four VMRs that "showed covariation with body mass index consistently at two study visits and were located in or near genes previously implicated in regulating body weight or diabetes." See our sister publication GenomeWeb Daily News' coverage of the study, here.