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Fig. 1. Expression of limk1 in the developing Xenopus retina. (A–F) Xenopus embryos processed for wholemount in situ hybridization using antisense RNA probe for limk1. Whole embryos show a restricted pattern of limk1 expression. The eye, otic vesicle, areas of the brain and the nasal placodes all express limk1 mRNA at stage 30 (A). The pattern is maintained, but stronger in the eye and brain, at stage 35/36 (B). Transverse vibratome sections through labelled embryos shows the changing pattern of limk1 in the retina. At stage 28, the optic vesicle has not yet invaginated and there is a patch of limk1 expression in the dorsal/central retina that spans the width of the tissue (C). By stage 30, the optic cup is present and limk1 is expressed in the inner layers that will become the GCL () and the inner nuclear layer (INL) (not labelled) (D). Expression has spread to the dorsal ciliary marginal zone (CMZ; white arrowhead), but is still absent from the ventral CMZ (black arrowhead). Expression in the central retina has weakened slightly at stage 33/34 (E), while the dorsal CMZ, ventral retina and ventral CMZ show robust expression. The divisions between the emerging layers are shown by the white lines in E (from lens outward is GCL, INL, ONL). limk1 expression in RGCs begins to decrease at stage 35/36 (F), but is still strong in the INL and CMZ. A, anterior; br, brain; D, dorsal; e, eye; np, nasal placodes; nr, neural retina; ot, otic vesicle; P, posterior; V, ventral. Scale bar in C is 50 μm. |
