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Fig. 3. Expression of Xversican mRNA in trunk neural crest cells and mesodermal derivatives in Xenopus embryos. Dashed lines indicate the level of the sections. (A) Diagram of the Xenopus trunk neural crest migration pathways, modified from Collazo et al., 1993. (B,C) Lateral views of stage 26 and 28 embryos respectively, showing Xversican transcript in trunk NCC migrating into the fin (compare arrows in (B,C), in the cardiac field (cf) (see also C, pronephrus (p) and pronephric ducts (pd). Xversican mRNA is localized in the caudal presomitic mesoderm of the tailbud (white arrow) and in branchial arches (see Fig. 3). (C Transverse vibratome section showing Xversican expression in the cardiac field (cf) and in the trunk NCC migrating, along the dorsal pathway, into the fin (arrowhead). A faint signal is still detectable in the ventral floor plate (arrow), while somites (so), labelled with the muscle cells specific marker 12/101 antibody, do not express Xversican. (C) Transverse vibratome section showing Xversican mRNA distribution at trunk level. NCC expressing Xversican are clearly detectable into the dorsal fin (arrowhead). Labelling signal appears in the ventro-medial portion of the somites (so), around the neural tube (nt) and the notochord (no) and in the ipochord (arrow), whereas no expression could be detected within the myotomes stained with the 12/101 specific antibody. (C Horizontal section showing somites stained with the 12/101 antibody and the metameric distribution of the Xversican transcript in the sclerotomic portion of the somites (arrow). (D,D At stage 41 Xversican expressing cells dispersed into the dorsal and ventral fin are still visible. D, dorsal trunk NCC pathway; V, ventral trunk NCC pathway. |
