Patterning of the mammalian kidney

Abstract

The mature mammalian kidney is composed of thousands to hundreds of thousands of nephrons, the basic functional unit responsible for physiologic control of water/salt balance and the removal of toxic bioproducts of metabolism from the body. The nephron is a composite structure composed of a highly organized, physiologically regionalized tubular epithelium, the renal tubule, a vascular supply and an epithelial collecting duct system that removes urine from the kidney. Our principal interest lies in understanding the molecular and cellular mechanisms that underlie the formation and patterning of the renal tubule. I will discuss recent data that highlight the importance of Wnt signaling in the regulation of a mesenchymal-to-epithelium transition that generates the renal vesicle, the primordium of the renal tubule. I will also describe a new effort we have launched, the Kidney Molecular Atlas Project (KMAP) that is aimed to provide a resource for the community. We propose to map in detail the expression of all transcriptional regulators, signaling factors, and their receptors in the developing mouse kidney to provide a detailed molecular anatomy of kidney development. Further, we will generate a number of novel transgenic strains to clarify the relationships among cell populations in the developing kidney and to facilitate rapid genetic manipulations in specific cell populations.