Localization of ChM-I protein in the decidua. (A and B) Visualization of invading fetal tissue through the decidua. Female mice were mated with homozygous EGFP transgenic male mice. At 7.5 days p.c., decidual capsules were dissected from the pregnant mice, fixed, and cryo-sectioned. Semi-serial sections were stained with HE (A) and anti-PECAM-1 antibodies (B, red), respectively. Fetal tissue (green) invading through the maternal decidua was observed under a fluorescence microscope. (C and D) Localization of ChM-I protein and PECAM-1-positive cells. Cryo-sections of 7.5 days p.c. tissues were double-immunostained with anti-ChM-I antibody (green) and anti-PECAM-1 antibody (red), and counterstained with DAPI (panel D). All images are representative of at least three independent experiments. epc, ectoplacental cone; em, embryo; dec, decidua. Bars in panels A-C, 200 μm; Bar in panel D, 50 μm.