Drosophila Transposable Elements: Mechanisms of Mutagenesis and Interactions With The Host Genome

Abstract

Publisher Summary This chapter discusses the transposable elements of Drosophila . The chapter also discusses the mechanisms of mutagenesis and interactions with the host genome. Most spontaneous mutations in yeast and Drosophila are caused by the insertion of transposable elements. There are many examples of transposon-induced mutations in vertebrates and several recent reports have shown de novo insertions of transposable elements resulting in inheritable genetic defects or neoplastic transformation in humans. Therefore, the generation of mutant phenotypes by the insertion of transposable elements may be an evolutionarily general phenomenon that deserves study for both basic and practical considerations. In Drosophila, transposable elements may insert into genes and cause mutant phenotypes by a variety of mechanisms, the nature of which depends on the location of the insertion site with respect to the different structural and functional domains of the affected gene. Transposable elements may contain splice consensus sequences that when inserted into the transcription unit of a gene could result in aberrant processing patterns, or they may contain transcription termination signals that could cause premature termination of transcription of the mutant gene. Transposable elements also carry sequences necessary for transcription initiation—such as enhancers—that could alter the pattern of expression of adjacent genes.