TUBULOGENESIS FROM ISOLATED SINGLE CELLS OF ADULT MAMMALIAN KIDNEY - CLONAL ANALYSIS WITH A RECOMBINANT RETROVIRUS

The adult mammalian kidney tubule epithelium exists in a relatively do rmant, slowly replicative state but has a large potential for regenera tive morphogenesis following severe ischemic or toxic injury. Under se lective serum-free growth conditions, which included epidermal growth factor and retinoic acid, a subpopulation of renal proximal tubule cel ls isolated from adult rabbit kidney were grown in cell culture. These cells possessed two important characteristics: 1) an ability to diffe rentiate morphogenically into tubule structures when grown in three-di mensional collagen gels and 2) a high capacity for self-renewal, since cell Lineage analysis with a recombinant retrovirus demonstrated that in vitro tubulogenesis arose from clonal expansion of a single cell. Thus individual cells in the adult kidney have retained the ability fo r kidney tubulogenesis in vitro.