Xenbase Image ID: 48086

Fig. 6. Xsna expression during neural crest migration in Xenopus. Distribution of Xsna mRNA shown by in situ hybridisation under dark field illumination, with corresponding bright field views below (A-F) or to the right (G-I). Scale bar = 400 pm in E, G; 200 pm in A-D,F; 100 pm in H,I. A: Stage 23. Transverse head section showing strongly labelled mandib- ular aggregates of cephalic neural crest (c) migrating around the pro- spective brain (nt) and eye primordia (ee). B: Stage 22. Transverse head section. Arrows indicate Xsna expression in ventral prospective forebrain. C: Stage 24. Horizontal head section showing hyoid and branchial ag- gregates of cephalic neural crest (c) migrating into the prospective bran- chial arch region (ba). The hybridisation signal in the surrounding visceral arch mesoderm (v) conceals the outline of the aggregates. D: Stage 21. Anterior of sagittal section. Distinct expression in neural tube roofplate (rp) and trunk neural crest (c) above. Labelling in mesoderm (pm) and endoderm of pre-chordal plate also. E: Stage 23. Transverse anterior trunk section. No labelling in notochord (n), myotomes (my) and proneph- roi primordia in dorsal lateral plate (pn), while transcripts are still detected in sclerotome (s), dermatome (dm), and the rest of lateral plate (Ip). Labelling in neural tube roofplate (rp) and trunk neural crest (c). F: Stage 23. Extreme posterior transverse section of embryo in (E). Paraxial me- soderm not yet segmented (us) and notochord (n) is undifferentiated mesoderm. G: Stage 28. Horizontal trunk section. Strong expression in pre-migratory trunk neural crest cells (c) along midline between muscle blocks (my). H: Stage 28. Transverse trunk section. Strong expression in pre-migratory trunk neural crest cells (c) above the neural tube (nt). I: Stage 35. Transverse trunk section. Strongly labelled trunk neural crest cells (c) migrating (arrows) dorsally into fin (df) and ventrally around neural tube (nt) and notochord (n). a = anterior: ba = branchial arch region: c = neural crest; df = dorsal fin; dm = dermatome; e = endo- derm; ee = eye; ep = epidermis; Ip = lateral plate mesoderm: my = myotome; n = notochord; nt = neural tube; p = posterior; pm = pre- chordal mesoderm; pn = pronephros; rp = roofplate; s = sclerotome; us = unsegmented paraxial mesoderm; v = visceral arch mesoderm. Image published in: Essex LJ et al. (1993) Copyright © 1993. Image reproduced with permission of the Publisher, John Wiley & Sons. Gene Synonyms Species Stage(s) Tissue snai2.L slug, snai2-a, snai2-b, Snail2, xSlu, xslug, XSnail2 X. laevis Sometime during NF stage 22 to NF stage 24 cranial neural crest brain eye forebrain hyoid crest branchial crest pharyngeal arch sclerotome dermatome roof plate trunk neural crest snai2.L slug, snai2-a, snai2-b, Snail2, xSlu, xslug, XSnail2 X. laevis Throughout NF stage 21 endoderm mesoderm roof plate trunk neural crest prechordal plate snai2.L slug, snai2-a, snai2-b, Snail2, xSlu, xslug, XSnail2 X. laevis Sometime during NF stage 28 to NF stage 35 and 36 trunk neural crest Image source: Published Larger Image Printer Friendly View

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