In a paper published online in advance in PNAS this week, a team led by investigators at the University of Illinois at Urbana-Champaign surveys six gastrointestinal microbiomes drawn from three different domesticated vertebrates — two swine, two cattle, and two chickens — using "carefully curated deep 16S rRNA hypervariable tag sequencing data." The authors say that their analyses "strongly suggest that these microbiomes have, in fact, been assembled through processes that involve a significant non-neutral (niche) contribution."
A team led by researchers at the University of Texas at Austin this week shows that "a single exposure to a common-use fungicide (vinclozolin) three generations removed alters the physiology, behavior, metabolic activity, and transcriptome in discrete brain nuclei in descendant male [rats], causing them to respond differently to chronic restraint stress," revealing that ancestral exposure to an environmental compound "modifies how descendants of these progenitor individuals perceive and respond to a stress challenge experienced during their own life history."
Investigators at the University of Minnesota Medical School examine the effects of stress on different regulatory mechanisms of the KOR gene in a paper published online in advance in PNAS this week. The Minnesota team reports having found that "stress selectively increased the expression of KOR mRNA isoforms controlled by Pr1, and terminated at PA1 in specific brain areas including the medial-prefrontal cortex, hippocampus, brainstem, and sensorimotor cortex, but not in the amygdala or hypothalamus." Overall, the team adds, its "results revealed a common molecular mechanism underlying the effect of stress on selected chromatin regions of this gene at the cellular level and in the context of whole animal and identified a critical role for c-Myc in stress-triggered epigenetic regulation of the KOR gene locus."
Elsewhere in the Early Edition, a team led by researchers at the University of Durham investigate the value of modern genetic data to elucidate the origins of dog domestication by analyzing 49,024 autosomal SNPs in 19 wolves and 1,375 dogs, the latter representing 35 breeds. The team reports having uncovered conflicting evidence when correlating the earliest archeological dogs with the geographic locations of 14 breeds thought to be ancient. "These genetically distinct ancient breeds only appear so because of their relative isolation, suggesting that studies of modern breeds have yet to shed light on dog origins," the authors write in PNAS.