Fig. 4

Histopathological analysis of kidneys and ureters from Robo2 ^PB/PB mice with VUR. a Masson staining of a kidney from a newborn Robo2 ^PB/PB mouse with simple VUR revealed no scarring. b Kidney section from a Robo2 ^PB/PB mouse with hydronephrosis accompanied by multiple ureters depicted dilatation of the collecting tubule, thyroidization-type tubular atrophyimmature glomeruli, and abnormal capillaries surrounded by loose, undifferentiated mesenchymal tissue (c) Kidney section from a Robo2 ^PB/PB mouse with an abnormally small kidney accompanied by short dilated ureter depicted nearly complete loss of renal parenchyma, cyst formation and focal glomerular capillary tuft collapse (d) H&E staining of a ureter from a Robo2 ^PB/PB mouse with simple VUR revealed normal overall structure. e Multiple ureters from the same mouse as in B showed a thin layer of surrounding mesenchyme. f Ureter from the same mouse as in C showed a thin layer of ureter epithelium. g H&E staining of kidneys from adult Robo2 ^PB/PB mice with bilateral VUR. h H&E staining of kidneys showed glomerular hypertrophy and no inflammation. i Electron microscopy showed normal glomerular structure. Scale bars: 5,00 μm in A; 1,00 μm in b–c; 50 μm in d–f