Dicer expression in term and preterm chorioamniotic membranes. (A) Immunofluorescent staining showing ubiquitous expression in the cells comprising the chorioamniotic membranes. (B, C) The expression is also ubiquitous in the chorionic villi and umbilical cord, with more distinct immunoreactivity in the vascular endothelial cells and smooth muscle cells in both structures. (D) In the amnion, immunoblotting demonstrates decreased Dicer expression in TNL and TL cases compared to PTL cases. In the chorion-decidua, Dicer expression was substantially reduced in TL cases compared to PTL and TNL cases. The expression pattern of Dicer in the placenta is strikingly similar to those in the amnion and chorion. Of special note is that the molecular weights of Dicer in the chorioamniotic membranes and the placenta are different. The chorioamniotic membranes predominantly expressed a 219 kD (1,922 aa) full-length protein, while the placenta largely expressed 113 kD (997 aa) and 93 kD (820 aa) variants.