In the early, online edition of the Proceedings of the National Academy of Sciences, researchers from Harvard Medical School and New York University present findings from a candidate gene-based search for genetic factors that allow Mexican cavefish to survive in food-poor environments. The team performed targeted sequencing on genes suspected of contributing to metabolism, comparing cave-dwelling forms of the species with those residing in surface waters. The search uncovered mutations in a melanocortin 4 receptor-coding gene called MC4R that appear to contribute to cavefish adaptations such as starvation-resistance and binge eating behaviors in environments where food is plentiful.
Researchers from Argentina, the UK, and the US uncovered a splicing regulator that seems to mediate the splicing and circadian rhythm effects of altered temperature in the model plant Arabidopsis thaliana. As they report in another PNAS study, the investigators used phylogenetic clues to track down mutant alleles of a conserved spliceosome assembly factor called GEMIN2 that mediates temperature-related circadian period in the plant via alternative splicing events. "[O]ur results suggest that GEMIN2 attenuates the effects of temperature on the circadian period by modulating [alternative splicing] events associated with several core clock genes," they note, "most likely altering the overall balance required for proper temperature compensation of the clock."
Using a collection of Drosophila strains with random transposable element insertions, an international team led by investigators in Texas and the UK searched for genes contributing to fruit flies' propensity for ethanol consumption. After narrowing in on a fly strain showing lower-than-usual sedation after ethanol consumption, the researchers used DNA sequencing to trace this effect back to a gene coding for the Ras suppressor 1. Through RSU1 knockdown experiments in human cell lines and brain imaging studies on more than 1,300 adolescents genotyped for variants in the gene, the study's authors saw hints that the gene has ties to alcohol consumption in humans, too, regulating brain regions associated with reward-related processes.