Fig. 5. In situ analysis of Dp1-deficient conceptuses at E7.5. Decidua containing a wild-type (A,E,I) and three abnormal, presumptive Dp1 mutant (B-D,F-H,J-L) conceptuses were analyzed after serial sectioning. (A-D) Visualized with Hematoxylin and Eosin staining. (E-H) Immunohistochemical staining with TROMA1 to detect trophectoderm-derived tissue. (I-L) BrdU incorporation after a 30 minute in vivo labeling. The star indicates the position of the ectoplacental cone (EPC) and secondary trophoblastic giant (TG) cells at the proximal pole of the conceptus. The arrowhead indicates the position of a trophoblast giant cell at the distal pole of the wild-type conceptus.