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Fig. 4. X-Delta-2 is necessary for Hox gene expression during early development, prior to somite formation. X-Delta-2 morpholino (MO) was injected in the LHS of the embryo and the expression of Hoxb4 (A-D), Hoxc6 (E-H) and Hoxb9 (I-L) analysed by whole-mount in situ hybridisation at gastrula and neurula stages. Gastrula stage embryos (A,B,E,F,I,J) are shown form the vegetal side with dorsal to the top and neurula stage embryos (C,D,G,H,K,L) from the dorsal side with anterior to the top. At gastrula stage almost no expression of Hox genes was observed in the injected side (B: Hoxb4, 90%, n=21; F: Hoxc6, 94%, n=37; J: Hoxb9, 100%, n=30). At neurula stage Hoxb4 expression was shifted posteriorly (D: 79%, n=24), Hoxc6 expression was only slightly downregulated (H: 80%, n=25) and Hoxb9 expression was almost completely absent (L: 87%, n=88). The arrowhead indicates the injected side of the embryo. |
