Organogenesis of the Zebrafish Kidney

The nephron is the conserved functional unit of vertebrate kidneys and is composed of a glomerular blood filter attached to a segmented tubule. The gene regulatory networks governing nephron formation during embryonic development are poorly understood and are challenging to study in complex kidney types such as the mammalian adult (metanephric) kidney. By contrast, the zebrafish embryonic (pronephric) kidney offers a number of advantages including its linearly arranged, simple two-nephron structure, and ease of genetic manipulation. As the genes involved in nephrogenesis are largely conserved, the zebrafish model can provide valuable insights into the core gene networks involved in mammalian nephron formation, with relevance to birth defects and disease. In this chapter we review the structure and function of the zebrafish pronephric nephron and summarize our current understanding of the gene regulatory networks and signaling pathways that control the formation of glomerular and tubule cell types.