The affairs of daughterless and the promiscuity of developmental regulators

Among the myriad accounts of newly discovered connections involving DNA sequences, biochemical activities, and developmental processes, those reported recently for the Drosophila gene daughterless (da ) are notable not only for the diversity and depth of the studies connected, but also for the strength and number of the associations. In this case, connections made through both genetic and molecular analysis have already related sex determination, dosage compensation, neurogenesis, immunoglobulin gene expression, and oncogenes. The summary presented here describes the convergence of these diverse and often very specialized studies and suggests some of the implications they may have regarding developmental regulators in higher eukaryotes.