An international team led by investigators at the Wellcome Trust Sanger Institute reports on findings from a functional profiling analysis of the Plasmodium genome. The researchers tapped nearly 2,600 barcoded knockout mutant versions of the P. berghei malaria parasite, producing pools of knockout mutants for competitive growth assays in mice. By tracking barcode abundance with a sequencing approach dubbed BarSeq, they got a look at the essential core genome for P. berghei and found evidence of widespread gene use by the parasite during normal blood growth. "At a single stage of its complex life cycle," the authors note, "P. berghei requires two-thirds of genes for optimal growth, the highest proportion reported from any organism."
Researchers from Portugal, Germany, and France explore ties between metabolic adaptation and tolerance to sepsis. By bringing together targeted gene expression profiles, blood glucose measurements, survival assay data, and more in mice with altered or enhanced levels of the iron-sequestering ferritin H chain gene FTH, the team saw hints that disease tolerance associated with that protein leads to metabolic adaptations related to glucose production. Based on results from these and other experiments, the authors conclude that sepsis disease tolerance "relies on a crosstalk between adaptive responses controlling iron and glucose metabolism, required to maintain blood glucose within a physiologic range compatible with host survival."
A team from the MRC Laboratory of Molecular Biology describes a self-inactivating form of the rabies virus that was developed to study genetic and functional processes associated with specific neural networks in the brain. By tinkering with components of a viral protein stability pathway, the researchers came up with a self-inactivating rabies (SiR) virus that's designed to be targeted to specific neural circuits and followed over time, with limited transcription. "SiR provides a virtually unlimited temporal window for the study of network dynamics and for the genetic and functional manipulation of neural circuits in vivo without adverse effects on neuronal physiology and circuit function," they report.