Xenbase Image ID: 75914

Fig. 1. Function of Hh and Wnt signals during neural induction, anteroposterior patterning and eye field development. Xenopus embryos were injected into the animal pole of a single blastomere at the 4-cell stage with the indicated constructs and nlacZ mRNA as a lineage tracer (red nuclei on injected right side). (A,A′) Control late gastrula in dorsal view depicting the neural plate marker Sox2 and the epidermal marker Cytokeratin. (B,B′,C,C′) XGli1 mRNA expands neural at the expense of epidermal tissue, while Gli3C′δClaI mRNA causes the opposite effect. (D,D′,E,E′) XWnt3a DNA promotes epidermal and dnXWnt8 mRNA neural development. (G–G′) Control embryos at neurula stage in anterior view (G,G′) and at tail bud stage in dorsal view (G′). Otx2 demarcates the developing cement gland, forebrain and midbrain (horizontal line), FoxG1 the telencephalon, En2 the posterior midbrain, and Krox20 the hindbrain rhombomeres 3 and 5 (bracket). Open arrowhead points to the anterior border of HoxC6 expression in the spinal cord. (H–H′,I–I′) XGli1 mRNA anteriorizes the brain, whereas Gli3C′δClaI causes very subtle posteriorization. (J–J′) XWnt3a DNA has posteriorizing activity. The arrow points to an expansion of Krox20 expression in neural crest cells. (K–K′) dnXWnt8 mRNA leads to anteriorization. (M) Control tail bud embryo in anterior view, showing Rx2A expression in the bilateral eyes. (N–O) XGli1 mRNAs diminish, whereas Gli3C′δClaI mRNAs expand the eye anlage. (P,Q) XWnt3a DNA leads to a smaller and dnXWnt8 mRNA to a larger eye anlage. (F,L,R) Summary of effects of Hh and zygotic Wnt signals on neural induction (F), anteroposterior patterning (L), and specification of the eye field (R). The indicated gene expression patterns were obtained in: B, 43/46; B′, 24/26; C, 48/49; C′, 41/52; D, 36/40; D′, 17/19; E, 57/57; E′, 64/68, H, 9/10; H′, 12/12 (FoxG1), 8/12 (En2); H′, 7/7 (Krox20), 11/11 (HoxC6); I, 11/13; I′, 18/20 (FoxG1), 15/20 (En2); I′, 17/26 (Krox20), 45/49 (HoxC6); J, 44/44; J′, 34/34 (FoxG1), 29/34 (En2); J′, 43/50 (Krox20), 12/17 (HoxC6); K, 42/45; K′, 37/37 (FoxG1), 29/37 (En2); K′, 15/15 (Krox20), 13/13 (HoxC6); N, 8/10; O, 17/20; P, 8/9; Q, 11/11 (Rx2A). Image published in: Min TH et al. (2011) Copyright © 2011. Image reproduced with permission of the Publisher, Elsevier B. V. Gene Synonyms Species Stage(s) Tissue sox2.L anop3, LOC108718087, mcops3, Sox-2, XLSOX-2, Xsox-2, XSox2 X. laevis Throughout NF stage 14 neural plate neuroectoderm krt12.4.L ck81, cytok, cytokeratin, E-keratin, epi-keratin, epidermal keratin, Epidermis-specific keratin, EpiK, epiker, EpK, epK, K81, xK81, xk81a, xk81a1 X. laevis Throughout NF stage 14 epidermis ectoderm non-neural ectoderm otx2.S otx-2, otx2-a, otx2-b, otxA, Xotx-2, Xotx2 X. laevis Throughout NF stage 16 eye primordium ectoderm neuroectoderm forebrain midbrain cement gland primordium foxg1.L bf1, foxg1b, LOC108700624, XBF-1, XBf1 X. laevis Throughout NF stage 16 forebrain telencephalon neuroectoderm en2.L En-2, en2-a, en2-b, eng2, engrailed 2, engrailed homolog 2, engrailed-2, maben, xen2 X. laevis Throughout NF stage 16 midbrain posterior neuroectoderm egr2.L EGR-2, Krox-20, krox20, XKr20, XKrox-20 X. laevis Throughout NF stage 24 hindbrain rhombomere R3 rhombomere R5 neuroectoderm hoxc6.S ACI, xeb1, XlHbox1 X. laevis Throughout NF stage 24 spinal cord neural tube rax.S rax-a, rax-b, rax1, rx, rx-1, rx1, rx1a, Rx2A, Xrax, Xrx1, Xrx1A X. laevis Throughout NF stage 24 eye primordium Image source: Published Larger Image Printer Friendly View

Return to previous page