Nephrogenesis

Nephrogenesis is the process of kidney formation in embryonic development. It is a complex and highly regulated process that involves the interaction of several cell types and signaling pathways.

Overview

Nephrogenesis begins around the fifth week of gestation in humans and continues until approximately 34-36 weeks of gestation. The process involves the formation of the nephron, the functional unit of the kidney, from the metanephric mesenchyme and the ureteric bud.

Stages of Nephrogenesis

Induction

The first stage of nephrogenesis is the induction of the metanephric mesenchyme by the ureteric bud. This interaction is mediated by several signaling pathways, including the GDNF/RET pathway and the FGF/FGFR pathway.

Nephron Formation

Following induction, the metanephric mesenchyme undergoes a process of mesenchymal-epithelial transition to form the nephron. This process involves the formation of a series of intermediate structures, including the renal vesicle, the comma-shaped body, and the S-shaped body.

Maturation

The final stage of nephrogenesis is the maturation of the nephron. This involves the differentiation of the various components of the nephron, including the glomerulus, the proximal tubule, the loop of Henle, and the distal tubule.

Regulation of Nephrogenesis

Nephrogenesis is regulated by a complex network of signaling pathways and transcription factors. Key regulators of nephrogenesis include the Wnt signaling pathway, the Notch signaling pathway, and the Hedgehog signaling pathway.

Clinical Significance

Abnormalities in nephrogenesis can lead to a variety of congenital anomalies of the kidney and urinary tract (CAKUT). These include renal agenesis, renal hypoplasia, and polycystic kidney disease. Understanding the mechanisms of nephrogenesis can therefore have important implications for the treatment of these conditions. Template:Embryology-stub Template:Kidney-stub