ABSTRACT
Initial interest in insecticide resistance genes in relation to non-drosophilid insect "iansgenesis foc~ased on the need for selectable markers to isolate putative germline transformation events rapidly (Thonnpson et al.. 1993). Given the recent success of eye coior genes and green fluorescen phenotypes that can be visually screened for (see Chapter 4 by Sarkar and Coll Higgs and Lewis). the need for dmg-resistant selectable markers is reduced so the purpose of this chapter not only to summarize attempts to use these genes as selectable markers themselves, but also to emphasize the extent to which we fully understand these genes, which still represent some of the only non-drosophilid marker genes in which the molecular basis of the phenotype we are trying to rescue is known. In other words. where the nature of both the gene product and the mutation causing the mutant phenotype is known. In this respect, resistance genes illustrate some of the critical practical problems we face, beyond those of vector integration, in actually trar-isfmming defined phenotypes such as disease refractoriness in mosquitoes.
