Due to their repetitive nature and the fact that they harbor regulatory elements, transposable elements (TEs) were early envisioned as drivers of the evolution of gene regulatory networks through their ability to spread ‘pre-built' regulatory elements in the genome. These first models have been recently refreshed by recent large-scale analyses of eukaryotic genetic regulatory landscapes, showing that TEs from various superfamilies can participate in the rewiring of different gene regulatory networks involved in key biological functions in various eukaryotic species. Nevertheless, the molecular mechanisms underlying the generation of TE-driven networks have been only characterized for a few cases and remains to be investigated at a larger scale, in particular in plants which have lagged behind animal studies.

In a recent study on maize (Fagny et al., 2021; doi.org/10.3389/fgene.2020.606285), we used a systems biology approach to investigate the enhancer-driven regulatory network of two tissues at different stages: leaves at seedling stage and ear-covering leaves at male flowering (husk). We have shown that husk-specific enhancers are enriched in MITEs, among which Pif/Harbinger elements harbor new Transcription-Factor Binding Sites. We will present how Pif/Harbinger sequences have contributed to the dissemination of potential regulatory elements throughout the maize genome and which functions they may have participated to.