Dr. Lisch is interested in the regulation and evolution of plant transposable elements. Transposable elements, or transposons, are, by far, the most dynamic part of the eukaryotic genome, and the majority, often the vast majority, of plant genomes are composed of these genomic parasites. Although they are an important source of genetic novelty, transposons can also be a significant source of detrimental mutations. Because of this, plants (and indeed all eukaryotes) have evolved a sophisticated "immune system" whose function is to detect and epigenetically silence them. Dr. Lisch's research centers on determining the means by which transposons are detected and then maintained in a silenced state. To do this, the Lisch lab has focused on MuDR, a transposon in maize that can be reliably and heritably silenced by a naturally occurring derivative of that element. Of course, epigenetic silencing is employed by plants and animals for a wide variety of other purposes, and epigenetic silencing pathways in plants are particularly diversified. However, whatever else they do, all of these pathways appear to be involved in transposon silencing as well, making transposons an excellent model for understanding how epigenetic information is encoded and propagated. Finally, transposon mobilization and subsequent silencing can have dramatic effects on the expression of plant genes. Current work in the Lisch lab combines a detailed analysis of MuDR transposon silencing with a global analysis of the effects of transposon silencing on plant gene function and phenotypic variation.