XB-IMG-153798
Xenbase Image ID: 153798
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Figure 4—figure supplement 4.
Expression of targets with persistent expression in placodes in whole-mount Xenopus embryos.
Expression dynamics for each target are shown across a range of developmental stages: A1–F1 show expression in neural plate stage embryos, A2–F2 show early tail bud stage embryos and A3–F3 show late tail bud stage embryos. B4–D4 and B5 –D5 shows sections at level indicated in B3–D3, respectively (dotted lines). (A) Expression of PPE marker gene Six1 is shown as reference for placodal domains (for details see Pandur and Moody, 2000; Schlosser and Ahrens, 2004). (B) Atoh1 is initially expressed at very low levels in presumptive otic placodes at neural plate stages (B1). This expression becomes more pronounced in the otic vesicle at early tail bud stages (B2) concomitant with the initiation of expression in lateral line ganglia and strong expression in the hindbrain (B2; asterisk). Expression becomes more pronounced in all three regions at late tail bud stages (B3 –B5). (C) Gfi1a is expressed at high levels in haematopoietic cells during neural plate stages (C1; asterisk). At early tail bud stages (C2) expression becomes more pronounced and diffuse, and expression is also initiated in the otic vesicle. At late tail bud stages Gfi1a is expressed in lateral line placodes as well as otic vesicles as the haematopoietic expression begins to subside (C3–C5). (D) During neural plate stages Isl2 is expressed in the profundal and trigeminal placodes and in the anterior placodal region along the anterior edge of the neural plate (D1). At early tail bud stages Isl2 expression is maintained in the profundal and trigeminal placodes/ganglia as well as in otic and lateral line placodes/ganglia and primary neurons in the spinal cord (D2; asterisk). Expression is maintained in cranial ganglia at late tail bud stages (D3–D5) and becomes apparent in the forebrain and lens (D3; arrowhead). (E) During neural plate stages Pou4f1.2 is expressed in the profundal and trigeminal placodes as well as in a stripe of primary sensory neurons (E1; asterisk; see Figure 4—figure supplement 5 for section). In early tail bud stages (E2) expression in the profundal/trigeminal placodes/ganglia and primary neurons is maintained, and expression in the otic and lateral line placodes is strengthened. Expression is maintained in all domains as well as in the cranial ganglia derived from placodes into late tail bud stages when expression becomes up-regulated in the retina (E3; diamond). Dotted line in E1 indicates the level of section shown in Figure 4— figure supplement 5. (F) Tlx1 is expressed in the presumptive ventral visceral arches at neural plate stages (F1; asterisk). This is maintained into early and late tail bud stages (F2 and F3), which also exhibit prominent expression in the profundal/trigeminal placodes and ganglia and the otic vesicle. Yellow and black arrows mark placodal expression. Bar in B4, C4 and D4: 100 μm (also for B5, C5 and D5, respectively). Abbreviations: pA: anterior placodal region; pAD: anterior lateral line placode; gAD: ganglion of the anterodorsal lateral line nerve; pE: epibranchial placode; pLl: lateral line placodes; L: lens; pL: lens placode; pM: middle lateral line placode; pO: olfactory placode; vOt: otic vesicle; pOt: presumptive otic placode; pPr: profundal placode; pP: posterior placodal region; pPL: posterior lateral line placode; pPrV: profundal/trigeminal placodes; pV: trigeminal placode; gV: ganglion of the trigeminal nerve. Image published in: Riddiford N and Schlosser G (2016) © 2016, Riddiford et al. This image is reproduced with permission of the journal and the copyright holder. This is an open-access article distributed under the terms of the Creative Commons Attribution license
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