Kidney development requires reciprocal interactions between the ureteric bud and the metanephrogenic mesenchyme. Whereas survival of mesenchyme and development of nephrons from mesenchymal cells depends on signals from the invading ureteric bud, growth of the ureteric bud depends on signals from the mesenchyme. This codependency makes it difficult to identify molecules expressed by the ureteric...

Class 3 semaphorins are guidance proteins involved in axon pathfinding, vascular patterning and lung branching morphogenesis in the developing mouse embryo. Semaphorin3a (Sema3a) is expressed in renal epithelia throughout kidney development, including podocytes and ureteric bud cells. However, the role of Sema3a in ureteric bud branching is unknown. Here we demonstrate that Sema3a plays a role ...

During kidney development, factors from the metanephric mesenchyme induce the growth and repeated branching of the ureteric bud, which gives rise to the collecting duct system and also induces nephrogenesis. One signaling pathway known to be required for this process includes the receptor tyrosine kinase RET and co-receptor GFR(&agr;)-1, which are expressed in the ureteric bud, and the secreted...

BACKGROUND Genetic analysis in the mouse revealed that GREMLIN1 (GREM1)-mediated antagonism of BMP4 is essential for ureteric epithelial branching as the disruption of ureteric bud outgrowth and renal agenesis in Grem1-deficient embryos is restored by additional inactivation of one Bmp4 allele. Another BMP ligand, BMP7, was shown to control the proliferative expansion of nephrogenic progenitors...

The homeobox gene Emx2 is a mouse homologue of a Drosophila head gap gene empty spiracles (ems) and is essential for the development of dorsal telencephalon (Yoshida, M., Suda, Y., Matsuo, I., Miyamoto, N., Takeda, N., Kuratani, S. and Aizawa, S. (1997) Development 124, 101-111). At the same time, Emx2 is expressed in the epithelial components of the developing urogenital system and, in Emx2 mu...

The molecular signals that regulate growth and branching of the ureteric bud during formation of the renal collecting system are largely undefined. Members of the bone morphogenetic protein (BMP) family signal through the type I BMP receptor ALK3 to inhibit ureteric bud and collecting duct cell morphogenesis in vitro. We investigated the function of the BMP signaling pathway in vivo by generati...

Development of the metanephric kidney depends on precise control of branching of the ureteric bud. Branching events represent terminal bifurcations that are thought to depend on unique patterns of gene expression in the tip compared with the stalk and are influenced by mesenchymal signals. The metanephric mesenchyme-derived signals that control gene expression at the ureteric bud tip are not we...

new study identifies a possible new function for endostatin, the potential cancer-killer that checks blood vessel growth. Within the developing kidney, endostatin may help regulate the branching that establishes the network of urine-collecting tubules. Cells in the ureteric bud divide and change shape to form the plumbing system of the kidney. Because endostatin inhibits blood vessel formation,...

In humans and mice, mutations in the Ret gene result in Hirschsprung's disease and renal defects. In the embryonic kidney, binding of Ret to its ligand, Gdnf, induces a program of epithelial cell remodeling that controls primary branch formation and branching morphogenesis within the kidney. Our previous studies showed that transcription factors belonging to the retinoic acid (RA) receptor fami...

The kidney develops through reciprocal interactions between two precursor tissues: the metanephric mesenchyme and the ureteric bud. We previously demonstrated that the zinc finger protein Sall1 is essential for ureteric bud attraction toward the mesenchyme. Here, we show that Kif26b, a kinesin family gene, is a downstream target of Sall1 and that disruption of this gene causes kidney agenesis b...