FIG. 4
YY1 has a widespread expression pattern in the developing embryo. Whole-mount in situ hybridization of E7.5 (A), E8.5 (B), E9.5 (C), and E12.5 (D) wild-type embryos with a YY1 antisense riboprobe. Hybridization of an E12.5 embryo with a YY1 sense riboprobe was included as a negative control (E). The Brachyury (T) riboprobe was used as a positive control (5a).