Overview

• The University of Tokyo-led team reports the finding in Nature Communications, identifying previously undetected extrachromosomal DNA in the oral microbiome.
• Inocles average about 350 kilobase pairs in length, placing them among the largest extrachromosomal elements known in humans’ microbial communities.
• Genomic analyses link the elements to Streptococcus salivarius and reveal genes tied to oxidative-stress resistance, DNA damage repair, and cell-wall functions.
• A sample-preparation method called preNuc, which depletes human DNA, combined with long-read sequencing enabled complete Inocle genome assembly.
• Based on the analyzed saliva samples, the researchers estimate roughly 74% of people may carry Inocles, and they plan culturing and computational studies to clarify functions and any clinical relevance.