Figure 2.
Fgl2/fibroleukin–deficient mice have hemorrhage at the feto-maternal interface. Zygotes and uterine tissue were examined by light microscopy and immunohistochemistry using a polyclonal anti-Fgl2 Ab. Feto-maternal interface of Fgl2/fibroleukin+/+ (Fgl-2+/+) zygotes at pc day 8.5, as assessed by hematoxylin and eosin staining (a) and Fgl2 immunostaining (b). Murine trophectoderm is positive for Fgl2 immunostaining. Fgl2/fibroleukin–/– (Fgl-2–/–) zygotes showed moderate to severe hemorrhage at implantation sites, with extravasation of maternal erythrocytes (rbc; arrowhead) between the mural trophectoderm and Reichert’s membrane (arrow) at the antimesometrial pole as assessed by hematoxylin and eosin staining (c) and negative Fgl2 immunostaining (d) (see Methods).