K8-deficient concepti are more sensitive to ConA-induced hematoma formation. Three K8+/−TNF+/− females were bred to a K8−/−TNF−/− male. 10 d postcoitus, the mothers were subjected to ConA treatment. 5 h after injection, the mice were killed, and the concepti were removed for histological analysis. Hematoxylin and eosin–stained sections revealed different degrees of bleeding. (A–F) Red blood cells are rendered in black by digital color replacement. Note that most of the hematoma occurs opposite the placenta (E and F). The identity of each specimen is indicated by the litter number and embryo number. Bar, 1 mm. Quantitative measurements of the hemorrhage size for every embryo from the three litters are shown in G, H, and I. The numbers above the horizontal bar of each panel indicate the embryo identification number of that litter. A statistical analysis of these numbers confirms that there is a statistical significant difference in the amount of hemorrhage in K8+/− versus K8−/− embryos (P = 0.006), but there is no such difference between TNF+/− (black bars) and TNF−/− (gray bars) embryos (P = 0.08).