Fig. 2. Phenotypic defects in integrin ß8-deficient mice. (A,B) E10.5 yolk sacs. The vasculature is less prominent and often pale in mutant embryos (B) when compared with wild type (A, arrow). (C,D) Side views of E10.5 embryos. The class A mutant embryo exhibits a smaller body size (D) compared with a wild-type littermate (C). An example of enlarged pericardiac cavities is shown in D (*). (E,F) Side views of E12.5 embryos. Intracerebral hemorrhage in a class B mutant embryo is shown (F, arrow) when compared with its wild-type littermate (E). (G,H) Side views of P0 wild-type (G) and mutant (H) pups. Severe hemorrhage in the mutant head is obvious (H, arrow). (I,J) The P0 mutant brain (J) shows characteristics of hydrocephalus (arrowhead) and exhibits visible hemorrhage compared with a wild type (I). (K,L) A cleft palate is obvious in a mutant neonate (L, arrow), but is absent in a wild-type littermate (K). mc, metencephalon; tc, telencephalon; op, optic vesicle; ot, otic pit; ba, bronchial arches; he, heart; fl, forelimb; hl, hindlimb.