RELATED TARGET ENHANCERS FOR DORSAL AND NF-KAPPA-B SIGNALING PATHWAYS

Drosophila dorsoventral (DV) patterning and mammalian hematopoiesis ar e regulated by related signaling pathways (Toll, interleukin-1) and tr anscription factors (dorsal, nuclear factor-kappaB). These factors int eract with related enhancers, such as the rhomboid NEE and kappa light chain enhancer, that contain similar arrangements of activator and re pressor binding sites. It is shown that the kappa enhancer can generat e lateral stripes of gene expression in transgenic Drosophila embryos in a pattern similar to that directed by the rhomboid NEE. Drosophila DV determinants direct these stripes through the corresponding mammali an cis regulatory elements in the kappa enhancer, including the kappaB site and kappaE boxes. These results suggest that enhancers can coupl e conserved signaling pathways to divergent gene functions.