Promoters to Express Cloned Genes Uniformly in Drosophila

Forcing ubiquitous expression of a given gene in transgenic Drosophila has become a powerful tool of molecular genetics. Gene misexpression usually causes a dominant phenotype and one may deduce potential functions for the gene from an analysis of this phenotype. Evidently, when a dominant phenotype arises, uniform expression must be inducible such that the ubiquitously expressing construct can be maintained in a silent state in the transgenic stock. Even more informative than uniform expression throughout the animal, is expression in a large patch of tissue, especially when the gene considered acts in a non-cell-autonomous fashion. Here we review the methods available to achieve uniform expression of any cloned gene in Drosophila . We then go on to discuss how expression can be made conditional and/or in large patches of tissue.