Establishing a Tomato Transposon Tagging System with Heterologous Transposons

Abstract

The study of maize transposons has proved to be not only interesting but also useful. Transposons, or transposable genetic elements, were first identified in maize (1), and were subsequently detected in all forms of life where they were looked for (2). Studies on transposon behaviour have given insight into cell lineages in development (3), into mechanisms which generate new variation on which natural selection can act (4,5) and into somatic processes which can modify gene expression during development (e.g. methylation- 6). Additionally, transposons have proved very useful for the isolation of new genes for which the biochemical properties of the gene product are too difficult or too poorly characterized to provide a route to gene cloning. This technique has been employed for the isolation of interesting genes from bacteria, Drosophila, maize and Antirrhinum. In particular, the maize regulatory genes C1 (7), R/Lc (8) and Vp1 (9) have been isolated with this technique, and also the developmental mutant Knotted (10). In Antirrhinum the anthocyanin biosynthetic gene pallida (encoding dihydroflavanol reductase) was isolated using transposon tagging (11), as was floricola a developmental gene required for the initiation of floral development, (E Coen, pers. comm.).