In PLOS Genetics, researchers from Stanford and Harvard Universities describe genetic events leading up to the acquisition of drug-resistance mutations by HIV. The group delved into sequence data representing HIV samples collected over time from 30 patients who began with treatment-sensitive forms of the virus and went on to develop drug resistant HIV. Results from the analysis indicate that resistance mutations turn up individually, coinciding with a temporary dip in the virus' genetic diversity in the time after of these each resistance mutations become fixed through a both hard and soft selective sweeps.
A team from the UK and the US published a PLOS One study that used genome sequencing to characterize three viruses from the Orbivirus genus: the Orungo virus, the Lebombo virus, and the Changuinola virus. With those sequences, researchers identified protein-coding sequences within each of the viruses and did a phylogenetic analysis that offers clues to the co-evolutionary events that have helped to shape interactions between each of the orbiviruses and their respective insect hosts. "The earliest orbiviral ancestor was a tick/tick-borne orbivirus which existed at least 225 [million years ago]," they note. "Mosquito or mosquito-borne orbiviral ancestors would have evolved from this ancestral virus followed by Culicoides [midge] or Culicoides-borne orbiviruses."
DNA methylation patterns in T cells in adults can offer a possible peek back at individuals' physical aggression during childhood, according to another PLOS One study. Researchers from Canada, Ireland, and France used methylated DNA immunoprecipitation, together with microarray analyses, to assess methylation marks in blood T cells from 21 women with or without a history of chronic physical aggression during childhood. In those women — and in 20 men tested for the validation phase of the study — the team detected a methylation signature that coincided with aggressive behavior in childhood. Among them: methylation marks in sequences near some genes implicated in prior aggression studies on adults.