An organ culture model for the study of metanephric development.

A murine whole organ metanephric culture system was designed to study the developmental aspects of mammalian nephrogenesis. Metanephros and ureteric bud were removed from CFI albino mouse embryos at 13.5 +/- 0.4 days gestation, and grown in Dulbecco's modified Eagle's Minimal Essential Medium supplemented with 20 per cent donor bovine serum at 37C in a mixed air--5 per cent CO2 environment. Under the experimental conditions employed, the metanephric explants showed organotypic tubular and glomerular epithelial development. A well-developed proximal tubule with microvilli, and characteristic intracellular organelles and intercellular junctions developed by 72 hours of culture. By 120 hours of culture, unique devascularized glomeruli consisting of parietal and visceral epithelial layers formed. The glomerular visceral epithelial cells formed foot processes and slit pore diaphragms, and produced islands of basement membrane. No endothelial or mesangial elements were present at any stage in organ culture development, indicating that advanced nephrogenesis can occur following initial epithelial-mesenchymal induction despite the absence of vascularization. The whole organ culture model system isolates renal structural development from the influences of perfusion and urine formation. The system thus affords the opportunity to study normal, as well as abnormal mammalian renal development under highly controlled experimental conditions.