Expression, regulation and function of the homeobox gene empty spiracles in brain and ventral nerve cord development of Drosophila

We analyse the role of the empty spiracles (ems) gene in embryonic brain an d ventral nerve cord development. ems is differentially expressed in the ne urectoderm of the anterior head versus the trunk region of tarry embryos. A distal enhancer region drives expression in the deutocerebral brain anlage and a proximal enhancer region drives expression in the VNC and tritocereb ral brain anlage. Mutant analysis indicates that in the anterior brain ems is necessary for regionalized neurogenesis in the deutocerebral and tritoce rebral anlagen. In the posterior brain and VNC ems is necessary for correct axonal pathfinding of specific interneurons. Rescue experiments indicate t hat the murine Emx2 gene can partially replace the fly ems gene in CNS deve lopment. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.