Bmp-2 downstream targets in mesenchymal development identified by subtractive cloning from recombinant mesenchymal...

ABmp-dependent in vitro model was used to identify cDNAs during the manifestation of mesenchymal lineages. This model involves the recombinant expression of Bmps (Bmp-2, Bmp-4-7) in murine mesenchymal C3H10T1/2 progenitors, which leads to the differentiation into three lineages: the osteogenic, the chondrogenic and the adipogenic lineage, albeit in varying efficiencies. By subtractive cloning, 21 Bmp-2-regulated cDNAs from C3H10T1/2 mesenchymal progenitors were identified; 20 were related to known sequences and 1 was not. During mouse embryonic development, many of these cDNAs are expressed in chondrogenic, osteogenic, and in adipogenic tissues. Novel findings include a G0/G1 switch gene (G0S2), which was demonstrated to be predominantly expressed in adipose tissue during late murine embryonic development. Furthermore, the membrane-standing glycoprotein autotaxin (ATX) is expressed, at precartilage condensations, joint regions, and during tooth development. An as yet undescribed cDNA, 29A, which encodes a putative secreted factor, is expressed in developing osteo-/chondrogenic tissues of vertebrae, ribs, tooth, and the limb bud. C3H10T1/2-progenitors, therefore, may serve as a legitimate model for the investigation of the Bmp-mediated events during mesenchymal differentiation.