NIDDK Recent Advances & Emerging Opportunities: Kidney, Urologic, and Hematologic Diseases

98 ­ Each human kidney contains about 1 million functional units that remove wastes from the blood, help control the body’s fluid balance, and regulate electrolyte balance. New research in mice could help explain how kidneys generate the correct number of functional units, called nephrons, during development. (Left panel) Mice treated to have fewer nephron progenitor cells (bottom) during development have fewer nephrons at birth than normal mice (top)—a difference that persists into adulthood, even though overall kidney size is similar. (Right panel) Three dimensional renderings of the kidney internal structure during development show differences in size and extent of nephron branching between the normal (top) and progenitor-cell-limited (bottom) mice. As nephrons are not replaced after birth, having a lower nephron number at birth may cause kidney problems later in life. These new findings could contribute to efforts to understand and treat kidney disease.