Researchers from Harvard University and elsewhere unveil VirScan, a screening technique that can identify an individual's complete viral history from a small blood sample, in Science this week. The method analyzes antiviral antibodies using immunoprecipitation and massively parallel DNA sequencing of a bacteriophage library that displays proteome-wide peptides from all human viruses. The investigators assayed more than 100 million antibody-peptide interactions in 569 people from across four continents and detected antibodies to an average of 10 viral species per person — although at least two individuals encountered 84 viral species. The findings reveal strongly conserved immune responses, or "public epitopes," for each virus, suggesting that they may elicit highly similar antibodies. The investigators also suggest that VirScan might be adapted to study the antibody response to other members of the human microbiome such as bacteria or protozoa.
Also in Science, a team of UK scientists reports on the use of a new technique for observing the progression of live human oocytes to uncover the basis for the particularly high rate of chromosome segregation errors in these egg progenitor cells. Using an experimental system for ex vivo high-resolution fluorescence microscopy of human oocytes freshly harvested from women undergoing gonadotropin-stimulated in vitro fertilization cycles, the group found that the assembly of the meiotic spindle, which divides chromosomes in a parental cell into two daughter cells, takes more than 16 hours, as compared with about four hours in mouse oocytes. The prolonged spindle assembly process in human oocytes leaves spindles unstable and particularly prone to chromosome segregation errors, the researchers say.