The impact of transposable elements on gene and genome evolution

Abstract

Transposable elements (TEs) are fragments of DNA than can move, or transpose, from one location in the genome to another. Plant TEs are extremely powerful mutagens, inserting into genes and resulting in chromosomal inversions, duplications, and deletions. This feature of TEs has made them extremely useful as tools to gain genetic understanding of the plant genome. However, in addition to their well-described destructive roles as mutagens and molecular parasites on a generation-to-generation timescale, TE activity also has a creative side, constructing novel features in the genome on an evolutionary timescale. The ability of TEs to naturally alter the genome has made them excellent molecular mechanics, generating novel regulator regions, coding regions and chromosomal loci. Occasionally, some of this genomic tinkering generates useful products and is therefore selected for. This chapter explores the creative (rather than destructive) aspects of TE activity.