Fig 2: Expression of AQP1 is associated with AQP9 protein level in oligohydramnios patients. Immunohistochemical staining of AQP1, AQP3, AQP8 and AQP9 was performed in placenta in normal AF volume group and oligohydramnios group (a–h). Immunohistochemical staining of AQP1, AQP3, AQP8 and AQP9 was conducted in amnion epithelial cells and chorion in normal AF volume group and oligohydramnios group (i–p). Bar 50 μm

Fig 3: AQP9 expression is decreased in AQP1 siRNA transfected WISH cells. Relative mRNA expression of AQP1, AQP3, AQP8 and AQP9 was measured by RT-PCR in WISH cells after AQP1 siRNA transfection. P < 0.05 vs control siRNA transfection (a). Expression of AQP1, AQP3, AQP8 and AQP9 proteins was detected by western blotting in AQP1 siRNA transfected WISH cell (b). Quantitative data for control siRNA and AQP1 siRNA protein were presented in the histogram (b′)

Fig 4: AQP1 knockout mice exhibit a decrease of AQP9 protein in placenta and foetal membrane and an increase of AQP8 protein in foetal membrane. Expression of AQP1, AQP3, AQP8 and AQP9 proteins was measured by western blotting in placenta at 13.5 GD (a–a′) and 16.5GD (b–b′). Expression of AQP1, AQP3, AQP8 and AQP9 proteins was determined by western blotting in foetal membrane at 13.5 GD (c–c′) and 16.5GD (d–d′). Quantitative data for each AQP protein were presented in the histogram (a′–d′)