In PLOS Genetics, researchers from the University of Kentucky and the Salk Institute explore the mechanisms of programmed genome rearrangements that occur in the sea lamprey, Petromyzon marinus, during development. The team used labeled immunofluorescent antibodies to follow methylation and histone marks during sea lamprey development, which involves the loss of some 20 percent of the sea lamprey genome from somatic cell lineages. The study's authors found that methylation was largely muted during early sea lamprey development, except in structures such as micronuclei, outside of the nucleus. In early embryogenesis, they say, it appears such micronuclei are enriched for repressive chromatin marks, contributing to DNA loss during subsequent cell divisions in a process that resembles chromosome lagging.
A team from Brazil sees evidence for Zika virus particles in saliva and urine of individuals with Zika virus during the acute phase of infection. As they report in PLOS Neglected Tropical Diseases, the researchers attempted to identify and quantify Zika virus RNA in nine urine samples and five saliva samples from nine Zika virus-infected individuals in Rio de Janeiro, Brazil, using RT-PCR, RT-qPCR, and a diagnostic kit designed to differentiate Zika virus infection from infection with Dengue virus or Chikungunya virus. Their results suggested Zika virus nucleic acids can turn up in urine and saliva during acute infection, prompting them to caution of "potential alternative person-to-person infection routes beyond the vectorial transmission."
Finally, Korean researchers reporting in PLOS One describe their search for genetic factors that mitigate the onset and features of an inherited Creutzfeldt-Jakob disease-associated mutation called V180I in the prion protein gene PRNP. The researchers assessed whole-genome sequencing on five individuals with genetic Creutzfeldt-Jakob who had the V180I mutation, which is reportedly the most common cause of the inherited prion disease in East Asia. Compared with sequences in the genomes of 145 unaffected individuals, the investigators identified some 18.6 suspected variants in the genetic Creutzfeldt-Jakob cases — a set they narrowed down to 29 candidate variants.