Fig. 3. Keratin inclusion bodies disrupt cell-cell adhesion and disrupt the organization of Mrj-deficient chorionic trophoblast cells. (A) Mrj expression (red) in a wild-type chorion at E8.25. (B,C) K18 expression (red) in wild-type (B; +/+) and Mrj-deficient (C; -/-) trophoblast stem (TS) cells. DNA is blue. (D) Ultrastructure of a keratin inclusion body (arrowheads) within a Mrj^-/- chorionic trophoblast cell at E8.25. (E-H) K18 expression (red) in wild-type (E,F) and Mrj^-/- (G,H) chorionic trophoblast cells at E8.25. (F,H) Higher-magnifications of boxed regions in E and G, respectively. (I-L) Morphology of Mrj mutant chorionic trophoblast cells in vivo (J) and in vitro (L) in contrast to wild-type cells (I,K). (M-P) Desmoplakin (Dp) expression (red) in wild-type (M,N) and Mrj^-/- (O,P) chorionic trophoblast cells at E8.25. (N,P) Higher-magnifications of boxed regions in M and O, respectively. (Q,R) Desmoplakin expression (green) in wild-type (Q) and Mrj^-/- (R) TS cells. (S,T) Electron micrographs of desmosomes (arrowheads) in wild-type (S) and Mrj^-/- (T) chorionic trophoblast cells at E8.25. ch, chorion; DP, desmoplakin; EPC, ectoplacental cone; me, chorionic mesothelium; TGCs, trophoblast giant cells; tr, chorionic trophoblast. Scale bars: 10 µm in A-C,E-R; 0.5 µm in D,S,T.