Genetic Control of the Spatial Pattern of Selector Gene Expression in Drosophila

Abstract

The body of the adult insect is an assemblage of highly specialized and widely differing structures and appendages derived from a series of homologous segments. In Drosophila, this diversity of form depends on the differential expression in each body segment of a specific set of genes known as selector genes (Garcia-Bellido 1975). Extensive genetic analysis has shown that most selector genes are organized in two clusters known as the Antennapedia complex (ANT-C) and bithorax complex (BX-C). The ANT-C genes are involved in controlling the differentiation of anteriorly located body segments (in the head and thorax), whereas the BX-C is required for the differentiation of the posterior part of the animal (the thorax and abdomen).