Conferences and WorkshopsConferences and Workshops
EVOLUTION AND DEVELOPMENTand evolution
Biozentrum, University of Basel, Switzerland
The homeobox has identified a class of master control genes, which specify the bodyplan and encode transcription factors. The DNA binding domain of these transcription factors is the homeodomain, which has been highly conserved in evolution. The structure of the homeodomain and its complex with the DNA has been determined at atomic resolution by NMR spectroscopy. Specific amino acids involved in binding specificity and functional specificity have been identified. One of these homeobox-containing genes, which also has a second DNA-binding motif, a paired box, has been discovered and was found to be a universal master control gene of eye morphogenesis. This gene was identified by the eyeless mutations in Drosophila, Small eye in the mouse, and Aniridia in humans. These genes, which have a similar phenotype and expression pattern, share 94% sequence identity in the paired box, 90% in the homeobox, and several intron splice sites. By targeted expression of both eyeless and Small eye, we have been able to induce the formation of ectopic eye structures on the antennae, legs and wings of the fly. Therefore, eyeless is a master control gene regulating some 2500 genes involved in eye morphogenesis.