Fig. 4.

Adamts9 null embryos recapitulate the Pofut2 knockout phenotype. (A–D′) Comparison of gross morphology of E 7.5 Adamts9 wild-type (Adamts9 wt) and Adamts9 nullembryos (Adamts9^del/del) (A and C) and after hematoxylin and eosin staining of sections (B and D). Wild-type embryos (A and B) are similar to those described in Fig. 1(A–B′). In contrast, the epithelia of Adamts9 mutants (C–D) were disorganized and the visceral endoderm lacked apical vacuoles, similar to that observed in Pofut2 knockouts (Fig. 1C–D′). White arrowheads in panel D′ point to the absence of apical vesicles in Adamts9 mutants. (E–G) Whole-mount in situ hybridization comparison of Adamts9 wild-type and knockout embryos at E 7.5. (E) Bmp4 was not expressed in Adamts9 mutants, similar to that observed in the Pofut2 knockout (Fig. 1G). (F) Brachyury (T) was expressed in a truncated domain in 1/5 Adamts9 mutants, but was absent in 4/5 embryos. (G) Snail was expressed weakly in 1/3 Adamts9 mutants. Embryos are oriented proximal up and distal down. Wild-type embryos are oriented anterior to the left and posterior to the right. The anterior posterior orientation of Pofut2 mutants is not known.