By analyzing genomic data from ancient Caribbean islanders, an international team led by scientists from the Max Planck Institute and Leiden University have uncovered new details about the earliest humans to populate this region. As reported in this week's Science, the researchers obtained genome-wide data on 93 people who lived in the Caribbean between 3200 and 400 cal. BP. They find evidence of at least three separate dispersals into the region, including one early dispersal into the Western Caribbean that was apparently connected to radiation events in North America and was followed by an expansion from South America. Other findings include genetic differences between the early settlers and the newcomers from South America with almost no evidence of admixture. GenomeWeb has more on this, here.
A Harvard Medical School team describes in Science a new method that uses DNA-barcoded microbial spores to rapidly determine object provenance. The technique, they say, holds potential for a wide range of applications such as tracking food contamination. The researchers designed nonredundant DNA barcodes that do not encode any gene, which were integrated into the genomes of synthetic, nonviable Bacillus subtilis and Saccharomyces cerevisiae spores. The engineered spores, the scientists write, can be manufactured at scale using existing methods and are easily dispersed onto objects or the environment where they persist for long periods, and the barcodes can be read using different tools including the CRISPR-based platform SHERLOCK.
The SARS-CoV-2 pandemic has highlighted the need for diverse sets of diagnostic approaches to control disease outbreaks, as well as new paths for the rapid validation, approval, and manufacture of tests, according to a group of Massachusetts General Hospital Research Institute scientists. Writing in Science Translational Medicine, they break down the types of tests currently available for SARS-CoV-2, discuss their strengths and limitations, and call for broad and repeated testing initiatives to contain the ongoing outbreak.