Skip to main content
Premium Trial:

Request an Annual Quote

PNAS Studies Assess Soil Viruses, Memory Impairment Retrotransposons, More

Editor's Note: Some of the articles described below are not yet available at the PNAS site, but they are scheduled to be posted some time this week.

Researchers at the University of California, Berkeley, the Lawrence Livermore National Laboratory, and elsewhere present findings from a metatranscriptomic analyses of RNA viruses in soil samples from four distinct habitats tested over time around a potted wild oat plant. Using RNA sequence profiles for 48 soil samples collected across the span of 22 days from rhizosphere, detritosphere, rhizosphere plus root, and unamended soil sites, the team identified diverse RNA virus sequences in the soil and sequences stemming from apparent viral hosts such as fungi or Proteobacteria, along with their dynamics and potential contributions to the broader carbon cycle. "These results greatly expand the known diversity of viruses and contribute to understanding microbial interactions in soil with major implications in carbon cycling," the authors report.

A team from the US and Germany describe apparent ties between memory impairment and a group of retrotransposons known as endogenous retroviruses, which were previously implicated in cognitive decline in Drosophila fruit flies. To explore a potential role for endogenous retroviruses in mammals, the researchers in two mouse models, relying on RNA sequencing, PCR, immunohistochemistry, and other molecular and behavioral assays to narrow in on a rise in ERV activity in the hippocampus in mice with memory impairments related to the same brain region. Based on these and other findings, the authors suggest that "chronic [endogenous retrovirus] activation is associated with cognitive impairment, measured with hippocampus-related tasks, in mouse models."

Princeton University and Simons Foundation researchers report on an improved, "photoswitchable" form of MEK1, a gene that codes for an enzyme that activates the ERK signaling pathway. After demonstrating that an earlier version of photoswitchable MEK1 (psMEK) had sub-par functionality in vivo in Drosophila fruit fly embryos expressing psMEK compared with wild type versions of the gene, the team came up with a gain-of-function, destabilizing mutation-based approach to boost the activity of photoswitch-activated MEK in vitro and in Drosophila and zebrafish models. "Our approach for optimizing and tuning light-activated protein kinases is not limited to MEK," the authors note, "and can be used to systematically extend the capabilities of light-activated regulatory enzymes.

The Scan

Latent HIV Found in White Blood Cells of Individuals on Long-Term Treatments

Researchers in Nature Microbiology find HIV genetic material in monocyte white blood cells and in macrophages that differentiated from them in individuals on HIV-suppressive treatment.

Seagull Microbiome Altered by Microplastic Exposure

The overall diversity and the composition at gut microbiome sites appear to coincide with microplastic exposure and ingestion in two wild bird species, according to a new Nature Ecology and Evolution study.

Study Traces Bladder Cancer Risk Contributors in Organ Transplant Recipients

In eLife, genome and transcriptome sequencing reveal mutation signatures, recurrent somatic mutations, and risky virus sequences in bladder cancers occurring in transplant recipients.

Genes Linked to White-Tailed Jackrabbits' Winter Coat Color Change

Climate change, the researchers noted in Science, may lead to camouflage mismatch and increase predation of white-tailed jackrabbits.