The inventors have developed a system of transgenic mice in which the mutation found in human families, loss of the type II BMP receptor, is recreated in an inducible and tissue specific manner, to be used as an in vivo model with high molecular fidelity. The dominant negative transgene consists of a promoter, gene, and polyadenylation sequence. The promoter consists of 7 copies of the tet operon followed by the minimal CMVpromoter. The transgene consists of the mouse sequence for BMPR2. The protein produced will include the extracellular and transmembrane portions of the native protein but is miising the intracellular region. Bovine growth hormone polyadenlyation sequence was also included.