The utility of transposable elements as tools for the isolation of plant genes

Abstract

Transposable elements are segments of DNA which have the unique capability of being able to excise from one site in the genome and reintegrate into new, different sites elsewhere in the genome. When transposition takes place and integration occurs within a gene locus, mutations are frequently generated producing variegated or recessive phenotypes. This ability of transposable elements to act as mutagenic agents through their association with particular gene sequences has lead to the development of the procedure of transposon tagging or gene tagging in higher plants. Through this technique, transposable elements can be used to clone and isolate genes of interest for which little or nothing is known about the final product (i.e., polypeptide). This offers tremendous potential for the isolation of a variety of agronomically important genes, which are virtually impossible to recover by other currently available gene cloning methodologies. To date, the technique has been used successfully to isolate genes from corn and snapdragon. Using gene transfer technologies, the potential now exists to extend this approach to clone genes from other plant species. Advantages and limitations of transposon tagging for isolating plant genes will be discussed.