Mammalian Kidney Development: Principles, Progress, and Projections

The mammalian kidney is a vital organ with considerable cellular complexity and functional diversity. Kidney development is notable for requiring distinct but coincident tubulogenic processes involving reciprocal inductive signals between mesenchymal and epithelial progenitor compartments. Key molecular pathways mediating these interactions have been identified. Further, advances in the analysis of gene expression and gene activity, coupled with a detailed knowledge of cell origins, are enhancing our understanding of kidney morphogenesis and unraveling the normal processes of postnatal repair and identifying disease-causing mechanisms. This article focuses on recent insights into central regulatory processes governing organ assembly and renal disease, and predicts future directions for the field. Outline 1 An overview of cell players and cellular processes in metanephric kidney development 2 Regulating ureteric bud outgrowth and branching 3 The fate of the multipotent metanephric mesenchyme 4 Nephron induction via a mesenchyme-toepithelial transition 5 Patterning, segmentation, and specialization of the epithelial networks 6 Postnatal events in functional renal maturation 7 Reassessing renal disease, repair, and regeneration using developmental biology 8 Looking to the future