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.
In a study set to appear in the Proceedings of the National Academy of Sciences this week, researchers from the Broad Institute, Harvard's Center for Communicable Disease Dynamics, and elsewhere describe the wide range of genetic features that may lead to resistance to carbapenem resistance in Enterobacteriaceae bacteria. The team did whole-genome sequencing on 122 carbapenem-resistant Enterobacteriaceae and 141 carbapenem-susceptible bacteria collected prospectively at three hospitals in the Boston area and one in California over 16 months. The resistant bugs spanned eight species, with phylogenetic patterns supporting local transmission. Even so, the authors note, the sequence data did not point to pronounced hospital outbreaks and resistance mechanisms were diverse, encompassing some resistance mechanisms not described in the past.
A team from China and the UK explores the evolutionary basis of bamboo diet and pseudo-thumb similarities in the giant panda (Ailuropoda melanoleuca) and the red panda (Ailurus fulgens), animals from distinct families. The researchers sequenced and assembled a 2.34 billion-base red panda genome de novo, using DNA from a wild male, and improved the existing giant panda genome with new sequencing data and re-assembly. Their analyses of the 21,940 predicted protein-coding genes in the red panda genome and the giant panda's 23,371 genes led to two genes with potential ties to convergent limb evolution, along with convergent signatures related to bamboo-consumption, and pseudogenization of an umami taste receptor gene in both animals.
Finally, researchers from Iceland, the UK, and the Netherlands present evidence of apparent selection against genetic variants that were previously implicated in educational attainment. The Decode Genetics/Amgen- and University of Iceland-led team came up with allele-specific weightings for hundreds of thousands of markers identified through a prior genome-wide association study before looking at relationships between polygenic educational attainment score and reproduction in more than 100,000 Icelanders. "Using data from Iceland that include a substantial fraction of the population," the authors write, "we show that individuals with high scores tend to have fewer children, mainly because they have children later in life."