Identification of an ancient Bmp4 cis-regulatory element using fish and mouse

Abstract

Bone morphogenetic protein 4 (Bmp4) is a multi-functional, developmentally regulated gene and is essential for early mouse development. Little is known about the transcriptional regulation of Bmp4. To investigate the hypothesis that Bmp4 utilizes numerous long-range cis-regulatory elements to direct its repertoire of spatiotemporal expression patterns, we surveyed a 398 kilobase region of the Bmp4 locus for transcriptional activity. Our findings indicate multiple tissue-specific cis-regulatory elements reside greater than 28 kilobases 5' or 3' to the mouse Bmp4 transcription unit. We used comparative analyses to identify three noncoding sequences conserved across 450 million years of evolution that reside ~50-100 kilobases from the Bmp4 promoter and are maintained in a syntenic group across vertebrates. One of three ancient noncoding sequences reproducibly directed lacZ expression in embryonic mesoderm. Taken together, these experiments indicate an ancient, mesoderm-specific Bmp4 cis-regulatory element resides nearly 50 kilobases 5' to mouse Bmp4.