Fig. 2. Temporal and spatial expression patterns of XRnf12. (A) Northern analysis. The 3.5 kb transcript is expressed throughout early embryogenesis, while the 3.0 kb transcript disappears at stage 11. 18S rRNA stained with ethidium bromide served as a loading control. Numbers at the top are developmental stages. (B-D) Overlapping expression of Xlim-1, XRnf12 and Ldb1 in the gastrula mesoderm as revealed by whole-mount in situ hybridization of sagittally bisected gastrula embryos (stage 10.5). Animal side is to the top, dorsal to the right. Arrowhead, blastopore. (E-J) Co-expression of XRnf12 and Ldb1 in neurula and tailbud stage embryos. Dorsal is to the top, anterior to the left. Arrowhead indicates profundal-trigeminal placodal area; numbers in the bottom right of each panel are the developmental stages. (K-P) Co-expression of XRnf12 and Ldb1 as revealed by cross sections of stained tailbud embryos (stage 26). Upper, or left, panels are bright-field images; lower, or right, panels show DAPI staining. XRnf12 (EG,K-M) and Ldb1 (H-J,N-P) are similarly expressed throughout early embryogenesis. Turquoise staining inside of the embryos shown in the cross sections resulted from BCIP staining as NBT was depleted by strong staining in the epidermis. Both genes are expressed similarly in the neural tube along the AP axis. ba, branchial arches; dc, diencephalon; ey, eye; hb, hindbrain; hm, head mesenchyme; nc, neural crest; ov, otic vesicle; p, pronephros; pf, pronephric field; sc, spinal cord.