Skip to main content
Premium Trial:

Request an Annual Quote

This Week in PNAS: Apr 26, 2016

Researchers from the Fred Hutchinson Cancer Research Center and elsewhere report on molecular subgroups detected in human glioma samples that were analyzed using a combination of genomic data. The team used multidimensional scaling to assess single nucleotide changes, copy number alterations, transcriptome patterns, and methylation profiles generated by the Cancer Genome Atlas on glioblastoma and low-grade glioma tumors. The team identified three broad molecular sub-groups with distinct copy number, single base, and methylation alterations — including a group made up of both glioblastoma and low-grade glioma tumors — and eight molecular subtypes overall. 

Max Planck Institute for Evolutionary Anthropology researchers Svante Pääbo and Philipp Khaitovich, together with colleagues from Germany, China, Japan, and Russia, consider the consequences of adding a second glutamate dehydrogenase gene into the mouse genome. The team used a bacterial artificial chromosome to add GLUD2 — a gene normally found in humans and apes — to developing mice. Transcriptomic and metabolomics testing on the transgenic mice suggest that GLUD2 did not alter glutamate concentrations in the mouse cerebral cortex. Rather, the enzyme appeared to impact metabolic pathways important to postnatal neuronal brain development. 

Finally, a research duo from Duke University describes genetic features found in a plant pathogen called Coleosporium ipomoeae, commonly known as red rust. The investigators focused on C. ipomoeae that primarily infect pine trees, but is also capable of attacking at least three morning glory species found in the eastern US. Through field collection, cross-inoculation experiments, and more, they found that pathogen genotypes tend to stick to one host in a given community, though infections of other host species can occur in a non-local context. "Previous investigations of pathogens attacking a single host indicate that pathogen genotypes evolve a broad host range across host genotypes," they write. "By contrast, this investigation demonstrates that, in a pathogen attacking several host species, pathogen genotypes evolve to be highly host-specific."