Figure 4 Effects of vax2 overexpression on swimming tadpole embryos after injection of 75 pg of Xenopus coding-region RNA and 250 pg of β-galactosidase RNA (B, D, F–H, and J–L) or 150 pg of full-length human RNA (E, I, and M) into the left dorsal animal blastomere at the 8 cell stage, as compared to the injection of 250 pg of β-galactosidase RNA alone (A and C). (A) A st. 46 embryo injected with β-galactosidase RNA, dorsal view. On the injected side (left), the optic cup and the forebrain are connected by the thin optic nerve only (arrowhead). (B) A st. 46 embryo coinjected with Xvax2 and β-galactosidase RNAs, dorsal view. The optic cup and the forebrain are abnormally connected by a giant optic stalk (arrow). (C) The same embryo shown in A, laterally viewed from the β-galactosidase-injected side. Eye morphogenesis is complete. (D) The same embryo shown in B, laterally viewed from the vax2-injected side. The optic fissure remains wide open. (E) Ventral view of the injected side of a st. 46 embryo microinjected with VAX2 RNA. The optic fissure is open. (F–H) Transversal sections of st. 46 embryos injected with Xvax2 RNA. (J–L) Higher magnifications of F–H, respectively. On the injected side, the right side in F–H, a wide optic stalk-like structure abnormally joins the optic cup to the brain (arrows in J and K). At anterior levels (F and J), a continuous lumen can be detected connecting the brain ventricle and the eye (arrowhead in J). The defective invagination of the ventral optic cup is also evident (G, H, K, and L). (I and M) Transversal sections of a st. 46 embryo injected with VAX2 RNA showing that the aberrantly folded neural retina presents a plexiform layer (pl) and is dorsally covered by a photoreceptor layer (ph).
Image published in: Barbieri AM et al. (1999)
Copyright © 1999. Image reproduced with permission of the publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License.
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