A Canary In The Coalmine: What One Transposon In Maize Can Tell Us About Epigenetic Silencing In Plants

In order to interpret epigenetic marks such as DNA methylation and histone modification it is important to use model systems to unravel causal relationships.  Transposable elements represent a primary target of epigenetic regulation in eukaryotes, and thus can serve as an excellent model for understanding these relationships.  Using a naturally occurring transposon system in maize, which includes MuDR, a regulatory autonomous transposon and Mu killer, a RNA hairpin silencing trigger, we show how a single transposon can be used to detect a surprising degree of variation in epigenetic regulation in plants as they develop.  Our results suggest that the mechanism of silencing can vary dramatically depending on developmental time, the location of the target transposon and the part of the transposon being examined.