.... A number of genes are differentially expressed in response to the gradient, but how their borders of expression are established is not well understood. We present evidence that the BMP gradient, via the Smads, provides a two-fold input in regulating the amnioserosa-specific target genes such as Race . Peak...

... for the localized expression of zerknüllt ( zen ), which encodes a homeodomain transcription factor. We present evidence that zen directly activates the amnioserosa-specific expression of a downstream target gene, Race ( R elated to a ngiotensin c onverting e nzyme). A 533 bp enhancer from the Race promoter region...