Researchers from the University of Pavia in Italy and elsewhere report on findings from a genomic analysis of population history in Central America, focusing on the so-called Isthmo-Colombian region. Based on low-coverage ancient genome sequences for a dozen pre-Hispanic or early colonial representatives, along with genome-wide profiles for 84 individuals from seven present-day Panamanian populations, the team began teasing out the historical and current population relationships in the region during early peopling events and across the Late Pleistocene and Early Holocene periods. "Our analyses reveal that pre-Hispanic demographic events contributed to the extensive genetic structure currently seen in the area, which is also characterized by a distinctive Isthmo-Colombian Indigenous component," the authors write, noting that the region appeared to be home to a previously unappreciated Pleistocene population "that remained restricted to the Isthmian area, expanded locally during the early Holocene, and left genomic traces up to the present day."
A Massachusetts General Hospital- and Ragon Institute of MGH-led team explore neutralizing antibody production and other immune responses to messenger RNA-based SARS-CoV-2 vaccines in the face of viral variants with altered spike protein sequences. Using a neutralization assay and blood serum samples from 99 individuals who had received either one or both doses of the Pfizer or Moderna mRNA vaccines, the investigators tracked immune responses to 10 pseudoviruses containing spike protein alterations first identified in the UK, Brazil, the US, South Africa, and elsewhere. The assay results suggest that at least five of the pseudoviruses may be more difficult to neutralize, the authors warn, hinting that the "development of new vaccines capable of eliciting broadly neutralizing antibodies may be necessary to resolve the ongoing pandemic."
Finally, investigators from Stanford University and other US centers outline SARS-CoV-2 interactions with host proteins that they tracked down with the help of "comprehensive identification of RNA-binding proteins by mass spectrometry" (ChIRP-MS), comparative genomic, and CRISPR gene editing-based screening approaches. Building from 300 SARS-CoV-2-related host proteins found with ChIRP-MS, the team brought in CRISPR screening and interaction network data for other RNA viruses to search for antiviral contributors, focusing in on potential antiviral activity stemming from SARS-CoV-2 interactions with the mitochondria. "Altogether," the authors report, "these data provide insights into the specific mitochondrial factors that associate with SARS-CoV-2 RNA, likely contributing to a central role of mitochondria as intracellular hubs for antiviral activity."