Placental and heart abnormalities in Dlc1gt/gt embryos. (i) Immunofluorescent staining of the placenta of 10.5 days post coitum (dpc) Dlc1wt/wt and Dlc1gt/gt embryos with PECAM (CD31) antibody. Twelve micrometer thick frozen paraformaldehyde fixed placental sections were incubated with anti-PECAM-1 antibody and then with FITC conjugated secondary antibody. (ii) The yellow arrow indicates a continuous network of blood vessel in the placental labyrinth haematoxylin and eosin stained sections of placental labyrinth of 10.5 dpc Dlc1wt/gt and Dlc1gt/gt embryos. Black asterisks indicate fetal erythrocytes and the yellow asterisk indicates maternal red blood cells. (iii) Transverse section of the X-gal stained heart of 10.5 dpc Dlc1wt/gt and Dlcgt/gt embryos. The yellow asterisk indicates normal thick trabeculated ventricular wall; the red asterisk thin smooth atria wall; and the green asterisk with foetal erythrocytes.