Specific Sequencing of Mobilomes Reveals Real Time Transposable Element Activity in Rice

Transposable elements (TEs) are mobile genetic elements that constitute a major part of eukaryotic genomes. They represent a main source of genomic diversity and an evolutionary force in both plants and animals. Host genomes have developed epigenetic mechanisms to control and prevent their proliferation. However, under specific stress conditions or at precise developmental stages, some TEs can be remobilized and proliferate in plant genomes. Today, only a few active TEs have been identified in plants and the mobile part of the genome or mobilome, comprising these elements, is unknown. To address this question we developed a strategy of high throughput sequencing that detects TEs extrachromosomal forms aiming at establishing an unbiased repertoire of mobile TEs.

Our method successfully identified known active TEs in Arabidopsis thaliana and rice Oryza sativa samples with destabilized epigenomes. Furthermore, I will present the identification of a new active retrotransposon in rice, which is both controlled by epigenetic and genetic mechanisms. Altogether, our mobilome-sequencing method represents a novel approach to understand and evaluate the impact of real time TE mobility on plant genomes.