By analyzing the genomes of an ancestral African population with an unusually high incidence of schizophrenia, scientists from the University of Washington and their collaborators have identified genetic mutations that are more likely to be found in those with the disorder than healthy individuals. The team, which reports their findings in Science, analyzed DNA from around 1,800 South African Xhosas, about half of whom have been diagnosed with schizophrenia. The scientists note that they focused on this population because African populations harbor the greatest wealth of human genetic diversity. They find that those with schizophrenia are more likely than controls to harbor private, severely damaging mutations in genes that are critical to synaptic function. "The depth of genetic variation in Africa revealed this relationship with a moderate sample size and informed our understanding of the genetics of schizophrenia worldwide," the authors write.
By engineering a part of the bee microbiome, investigators from the University of Texas at Austin have developed a new approach that could be used to address two key threats to the honeybee population. As reported in Science, the researchers designed the symbiotic bee gut bacterium Snodgrassella alvi to express molecules in the insects that stably induce an RNA interference-based effect against the parasitic mite Varroa destructor and the pathogen deformed wing virus. "This symbiont-mediated RNAi approach is a tool for studying bee functional genomics and potentially for safeguarding bee health," the team concludes.
Single-cell sequencing of normal breast tissue from women with cancer-associated BRCA2 mutations reveals molecular patterns that are likely hallmarks of disease and that can be detected prior to histologic abnormalities, according to a new study in Science Advances. A team led by researchers from Harvard University analyzed sorted cell populations from non-cancerous breast tissues of BRCA2 mutation carriers and matched controls and find that cells from BRCA2 carriers exhibit DNA damage, as well as attenuated replication checkpoint and apoptotic responses. Notably, most of the tissues studied were deemed to be histologically normal by highly experienced breast pathologists. "Using these hallmarks of cancer predisposition will yield unanticipated opportunities for improved risk assessment and prevention strategies in high-risk patients," the authors write.