Expression of bone morphogenetic protein receptors in the developing mousemetanephros

While bone morphogenetic proteins (BMPs) 2, 4 and 7 have recently been impl icated in aspects of metanephric development, and expression-patterns of th ese ligands have been described in the developing metanephros, the distribu tion of BMP receptors in developing metanephroi remains unknown. In the pre sent study, in situ hybridisation histochemistry was used to localise mRNAs for BMP typed receptors (BMPR-IA and BMPR-IB) and the BMP type-II receptor (BMPR-II) in developing mouse metanephroi. At embryonic day 12.5 (E12.5) a nd E14.5 transcripts for BMP typed receptors were localised to the tips and body of the branching ureter as well as mesenchymal condensates, developin g vesicles and comma-shaped bodies. Localisation of BMPR-II transcripts was similar although expression was not observed in the body of the ureter. At E17.5, transcripts for all three receptors were localised in the nephrogen ic zone including ureteric tips, vesicles, comma- and S-shaped bodies as we ll the body of the ureter and in tubules. BMP type-I and type-II receptor t ranscripts co-localised with each other, in agreement with the well-documen ted evidence that BMPs signal via heterotetrameric complexes of typed and t ype-II receptors and with the previously reported metanephric expression pa ttern of BMPs. These patterns of receptor expression suggest that these mol ecules are important regulators of epithelial-mesenchymal interactions, nep hron development and ureteric branching morphogenesis. Copyright (C) 2001 S . Karger AG, Basel.