Efficient studies of long-distance Bmp5 gene regulation using bacterial artificial chromosomes

The regulatory regions surrounding many genes may be large and difficult to study using standard transgenic approaches. Here we describe the use of ba cterial artificial chromosome clones to rapidly survey hundreds of kilobase s of DNA for potential regulatory sequences surrounding the mouse bone morp hogenetic protein-5 (Bmp5) gene. Simple coinjection of large insert clones with lacZ reporter constructs recapitulates all of the sites of expression observed previously with numerous small constructs covering a large, comple x regulatory region. The coinjection approach has made it possible to rapid ly survey other regions of the Bmp5 gene for potential control elements, to confirm the location of several elements predicted from previous expressio n studies using regulatory mutations at the Bmp5 locus, to test whether Bmp 5 control regions act similarly on endogenous and foreign promoters, and to show that Bmp5 control elements are capable of rescuing phenotypic effects of a Bmp5 deficiency. This rapid approach has identified new Bmp5 control regions responsible for controlling the development of specific anatomical structures in the vertebrate skeleton. A similar approach may be useful for studying complex control regions surrounding many other genes important in embryonic development and human disease.