"we identify key roles for the Zelda and Zerknullt transcription factors in establishing the resulting expression domain and find widespread binding of insulator proteins to the Mad and Brinker-bound genomic regions. Analysis of embryos lacking the BEAF-32 insulator protein shows reduced transcription of a peak BMP target gene and a reduction in the number of amnioserosa cells the fate specified by peak BMP signaling."xsd:string