Rapid origin and turnover of genomic imprinting by transposable elements

Abstract

Genomic imprinting, the preferential expression of alleles based on their parent-of-origin, is an epigenetic mechanism that plays a key role in endosperm development and establishment of hybridization barriers. While imprinting is frequently associated with DNA methylation asymmetries and transposable elements (TEs), growing evidence suggests that this connection is not applying to all imprinted genes. This review synthesizes recent findings across different plant species, highlighting how TEs not only initiate imprinting through epigenetic reprogramming but also participate in its turnover, driving rapid evolutionary changes. We discuss the contribution of chromatin context to imprinting, and the emerging evidence of imprinting mechanisms independent of DNA methylation and TEs. We propose a dynamic and lineage-specific regulation of imprinting shaped by epigenetic context, TE activity, and developmental timing.