Xenbase Image ID: 23929

Fig. 6. Id3 is required for NC development downstream of Delta1. (A) Whole-mount in situ analysis of embryos injected with Delta1 mRNA (1 ng), DeltaStu mRNA (1 ng) or Delta1 MO (7.5 ng) as indicated. Note that Delta1 overexpression increases Id3 (a, 50% induced, n = 16). Conversely, Id3 is reduced in Delta1Stu mRNA or Delta1 MO injected embryos (b, 55%, n = 24; c, 67%, n = 18). (B) Activation of Notch signaling by injection of Delta1 mRNA (1 ng) rescues Id3 and Snail2 inhibition by Hairy2-GR in neurula embryos (a, 60% reduced, n = 23; b, 93% rescued, n = 15; c, 78% inhibited n = 18; d, 67% rescued, n = 30). Q-PCR analysis of Id3 (e) and Snail2 (f) expression in NC induced explants derived from embryos injected with Hairy2-GR mRNA (250 pg/blastomere) with or without Delta1 mRNA (500 pg/blastomere) as indicated (−, uninjected NC induced caps). Note that co-injection of Delta1 mRNA rescues Id3 and Snail2 repression by Hairy2-GR. (C) Id3 MO (15 ng) blocks Delta1 (1 ng mRNA, a–d; 500 pg mRNA, e) induction of Snail2, Sox10 and cell proliferation in embryos. Percentage of embryos with the indicated phenotype: a, 55% increased, n = 20; b, 70% inhibited, n = 26; c, 68%, increased n = 19; d, 62% reduced, n = 33. Percentage of embryos injected with Delta1 mRNA (500 pg) with or without Id3 MO (15 ng) showing increased pH3 staining (e). Note that co-injection of Id3 MO reduced Delta1 ability to stimulate cell proliferation (−, rhodamine dextran injected alone). Number of embryos examined is indicated. (D) Id3-GR mRNA (1 ng) injection partially rescues Snail2 in Delta1 (7.5 ng) depleted neurula embryos and Sox10 at tailbud stage but not in − DEX control embryos. Respective inhibition and rescue: a, 87% inhibited, n = 30; b, 70% unaffected, n = 37; c, 62% inhibited, n = 16; d, 67% unaffected, n = 21. Percentage of embryos injected with Delta1 MO (7.5 ng) with Id3-GR mRNA (1 ng) showing decreased pH3 staining (e). Note that Id3 partially rescues the inhibition of cell proliferation observed in Delta1 MO injected embryos. Number of embryos examined is indicated. In all panels, neurula embryos are viewed from the dorsal side, with the injected side revealed by LacZ staining oriented to the right. Tailbud embryos are viewed from the lateral side. Control and injected sides are shown. Image published in: Nichane M et al. (2008) Copyright © 2008. Image reproduced with permission of the Publisher, Elsevier B. V. Gene Synonyms Species Stage(s) Tissue sox10 Xenopus Throughout NF stage 28 neural crest otic vesicle branchial arch pharyngeal arch mandibular arch snai2 slug, snai2-a, snai2-b, Snail2, xSlu, xslug, XSnail2 Xenopus Throughout NF stage 14 neural crest id3 heir-1, id3-a, id3-b, xid3, xidia, xIdx Xenopus Throughout NF stage 14 neural crest anterior neural fold neural plate pre-chordal neural plate chordal neural plate chordal neural plate border Image source: Published Larger Image Printer Friendly View

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