Fig. 3

VUR experiment and histopathological analysis of the UVJ from Robo2 ^PB/PB and wild-type mice. a–d VUR experiment and histopathological analysis of intravesical ureters in a control mouse. e Bilateral VUR was observed in a Robo2 ^PB/PB mouse. f Macroscopic morphology of ureters and bladders was normal. The UVJs (arrowheads) were similar to the wild-type control (b). g Disorganized smooth muscle fibers (arrowheads) were found in intravesical ureter sections. h Electron microscopy of the intravesical ureters from Robo2 ^PB/PB mice with VUR showed normal overall structure but decreased muscle cell population, along with intercellular edema in the muscular layer (arrow) and intracytoplasmic vacuoles in smooth muscle cells (arrowheads). i–k VUR experiment and histopathological analysis of intravesical ureters were analyzed in a Robo2 ^+/+; Hoxb7/myr-Venus control mouse. l Unilateral VUR was observed in a Robo2 ^PB/PB; Hoxb7/myr-Venus mouse. m The ureter was mildly dilated on the left in a Robo2 ^PB/PB; Hoxb7/myr-Venus mouse with left VUR. n Higher magnification of the boxed region in M, demonstrating a wilder inner diameter in the refluxing ureter (arrow head). o-p The connection of the refluxing ureter relative to the bladder appeared normal in a Robo2 ^PB/PB; Hoxb7/myr-Venus mouse with VUR. Magnifications: (c and g) 400; (d and h) 1,500. Asterisks in d and h indicate the mucosa of the ureter