Kidney development branches out

For more than 40 years now, the developing kidney has served as a model par adigm for epithelial-mesenchymal interactions. The principles of inductive signaling, epithelial cell differentiation, and pattern formation are now b eing addressed with modern genetic and biochemical tools. In addition to th e mammalian kidney organ culture model, both zebrafish and Xenopus laevis d emonstrote great potential for investigating the molecular mechanisms of ki dney organogenesis within a whole organism. In this review, the papers pres ented in this special issue are discussed with respect to recent progress i n the renal development field. Coincidentally, ii has become increasingly c lear that progress made in renal development can impact our understanding o f the genetic basis of disease. (C) 1999 Wiley-Liss, Inc.