Researchers from the National Institute of Environmental Health Sciences describe gene expression and epigenetic shifts in mice with obesity-associated gut microbiome features. Using 16S ribosomal RNA gene sequencing, chromatin immunoprecipitation sequencing, and RNA sequencing, the team compared gut microbiome, chromatin, and colon epithelium gene expression patterns in mice provided with a high fat ("obesogenic") diet or a control diet. The results highlighted diet- and microbe-dependent differences in histone methylation and acetylation at active gene enhancers — shifts that were recreated in germ-free mice transplanted with microbes from high fat diet-fed mice. "These findings suggest that the gut microbiome, under specific dietary exposures, stimulates a reprogramming of the enhancer landscape in the colon, with downstream effects on transcription factors," authors say.
Identical twins appear to be more epigenetically similar to one another than non-identical twins, according to a Genome Biology study by investigators at the US Department of Agriculture-Agricultural Research Service, Baylor College of Medicine, and elsewhere. The team brought together array-based DNA methylation profiles at metastable epialleles in 97 pairs of monozygotic (identical) twins and 162 dizygotic (non-identical) twin pairs, identifying epigenetic overlap that was far more pronounced in members of the monozygotic twin pairs. "We discovered that many candidate [metastable epialleles] exhibit inordinately high epigenetic similarity in [monozygotic] twin pairs — a phenomenon we have termed 'epigenetic supersimilarity,'" the researchers write.
A Chinese Academy of Sciences-led team explores genetic features that have helped the Arabidopsis thaliana model plant adapt to Yangtze River basin, at the farthest southeastern reaches of the plant's native range. By sequencing 118 A. thaliana strains from either the Yangtze River region or parts of northwestern China, including the Altai Mountains, the researchers began untangling the history of Yangtze River strains, which split from an ancestral European/North African population an estimated 61,409 years ago. Since then, they say, the Yangtze River population appears to have undergone two distinct bursts of gene flow, along with more widespread dispersal in the region.