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Fig. 4. Localization of integrin a6 mRNA in early Xenopus embryos by whole-mount in situ hybridization. Stage 11.5 (A, dorsal side at top)
and 12.5 (B, anterior at right) Xenopus embryos express a6 mRNA in their dorsal ectoderm (y, yolk plug). (C) During neurulation (stage 15,
dorsal view, anterior at right), a6 mRNA is localized to the central region of the neural plate and the preplacodal ectoderm outlining the neural
ridge, with elevated expression in the future hindbrain. Transverse sections of equivalently staged embryos reveal a6 mRNA in the thickening
neural epithelium (arrowheads in G-I) as well as in the caudal ectoderm (I). (D) Lateral view of stage 15 embryo, reveals prominent a6 mRNA
expression throughout the neural tube, as well as in the caudal ectoderm surrounding the closed blastopore (arrowheads). (E) Lateral view of a
late neurula (stage 24), a6 mRNA is expressed throughout the neural tube, with prominent expression in the hindbrain, otic vesicle (arrowhead)
and optic lobe (arrow), as well as the notochord (n). (F) Longitudinal view of similar stage embryo reveals that expression in the neural tube is
restricted to the ventricular region. In addition, elevated levels of signal in the hindbrain represent expression in the otic vesicle and possibly
rhombencephalic neural crest lateral to the neural tube (arrowheads). |
