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Figure 3. paraxis is expressed in the paraxial mesoderm and neural tube. a, anterior; p, posterior. A: Stage 23 embryo stained for paraxis (purple) and the 12/101 antigen (brown) that is expressed in differentiated muscles. Note that paraxis expression is not found concurrent with markers of muscle differentiation. B: Stage 31 embryo stained for paraxis and 12/101. Note that, at this stage, most of the somitic muscles have already differentiated and no paraxis expression is observed, except in the tip of the tail bud. No expression in the neural tube is observed. C: Section of embryo shown in A. Note that, in the somite, paraxis is restricted to the dermatome (arrowhead). In addition, a clear expression in the neural tube is observed (arrows); n, notochord. D: Equivalent section of a stage 23 embryo showing expression of Xash in the sulcus limitans of the neural tube (arrows); n, notochord. E: Equivalent section of a stage 23 embryo showing expression of Xiro1 in the sulcus limitans of the neural tube (arrows); n, notochord. F: Summary of paraxis expression in the neural tube (nt) and somites (s), compared with sulcus limitans markers. n, notochord. Scale bars = 125 mu m in C-E. |
