In the early, online edition of the Proceedings of the National Academy of Sciences, an international team describes genetic variants that dial down the risk of conditions such as attention deficit hyperactivity disorder but bump up the euphoric effects associated with the drug d-amphetamine. Using clues from a past genome-wide association study of amphetamine response in hundreds of healthy individuals, the researchers searched for overlap between potential response contributors and variants implicated in studies of ADHD and/or schizophrenia. Among the SNPs with links to those diseases were variants with subtle ties to amphetamine response, they reported, including several variants that seem to boost amphetamine response and diminish the risk of the psychiatric conditions.
A team from Pennsylvania State University, Princeton University and elsewhere discovered a relationship between disadvantageous social environments and reduced telomere lengths in children with particular variant affecting genes in serotonin and dopamine-related pathways — work they present in another PNAS study. The researchers saw shorter-than-usual telomeres in nine-year-old African American boys enrolled in the Fragile Families and Wellbeing Study who were raised in harsh or disadvantaged environments, characterized by family instability, low income, and so on. Even so, that telomere effect seemed to vary somewhat depending on variant patterns present in dopamine and serotonin pathway genes.
Researchers from Canada and the Slovak Republic report on findings from their study of translational bypassing — the phenomenon by which ribosomes skip stretches of messenger RNA during translation. With the help of mitochondrial DNA sequencing, proteomics, and other approaches, the team uncovered dozens of elements that prompt translational bypassing in the yeast Magnusiomyces capitatus, an opportunistic pathogen, and other species from the same order. Based on their findings, the study's authors suspect that bypassing elements, or byps, rely on unused codons to avoid translation of some stretches of mitochondrial mRNA. "We hypothesize that byp-like elements have the potential to contribute to evolutionary diversification of proteins by adding new domains that allow exploration of new structures and functions," they write.