Identification of Extrachromosomal Circular Forms of Active Transposable Elements Using Mobilome-Seq

Active transposable elements (TEs) generate insertion polymorphisms that can be detected through genome resequencing strategies. However, these techniques may have limitations for organisms with large genomes or for somatic insertions. Here, we present a method that takes advantage of the extrachromosomal circular DNA (eccDNA) forms of actively transposing TEs in order to detect and characterize active TEs in any plant or animal tissue. Mobilome-seq consists in selectively amplifying and sequencing eccDNAs. It relies on linear digestion of genomic DNA followed by rolling circle amplification of circular DNA. Both active DNA transposons and retrotransposons can be identified using this technique.