Skip to main content
Premium Trial:

Request an Annual Quote

This Week in PNAS: Nov 17, 2015

The Max Planck Institute of Evolutionary Anthropology's Svante Pääbo and colleagues present findings from an effort to sequence DNA from two new Denisovan individuals whose ancient tooth samples were found in the same Altai mountain cave where the original Denisovan finger was discovered. The team successfully generated nuclear DNA sequences for an individual believed to be more than 50,000 years old whose mitochondrial DNA was sequenced previously. It also did both nuclear and mitochondrial DNA sequencing on a second, slightly younger individual before comparing both individuals to sequences from the original Denisovan, seven Neanderthals, and five modern humans. Based on these data, the study's authors conclude that Denisovans may have been more genetically diverse than Neanderthals, particularly within the mitochondrial genome. GenomeWeb has more on the study, here.

Researchers from the US, Switzerland, and Italy describe microRNA patterns that appear to coincide with patient outcomes and mutation drivers in non-small cell lung cancers. Using the NanoString nCounter miRNA expression assay, the team profiled miRNAs present in 67 non-small cell lung tumors, including 17 samples marked by an ALK translocation, 11 EGFR-mutated tumors, 15 tumors with KRAS mutations, and 24 triple-negative tumors free from EGFR, KRAS, or ALK alterations. It also tested 18 matched normal lung samples. Based on the miRNA profiles detected in the samples, the study's authors put together a diagnostic classifier comprised of three miRNAs that are differentially expressed in tumors with various driver mutations. Meanwhile, their results suggest expression of miR-769-5p and Let-7d-5p can offer clues to patient survival.

Finally, an international team reports on findings from a genome sequencing study of an insect species called Rhodnius prolixus, a vector for the Chagas disease-causing parasite Trypanosoma cruzi that has been used to model insect physiology in the past. The researchers put together an almost 703 million base genome assembly for R. prolixus that is believed to span nearly 95 percent of the insect's complete genome sequence at an average depth of eight-fold coverage. Using that sequence, they uncovered close to 15,500 predicted protein-coding genes, including genes and pathways that are expected to be of interest for understanding the insect's biology and its interactions with the T. cruzi parasite.