Xenbase Image ID: 156910

Fig. 3. Loss of Fzd3 as well as Alcam leads to defects in retinal lamination and cell adhesion. Transmission electron microscopy of Control MO (A-C, upper rows), Fzd3 MO (A, lower row), Alcam MO (B, lower row) and Pax2 MO (C, lower row) injected Xenopus eyes at stage 42. Specific cells are highlighted by dotted circles. Overview: Overviews of the eyes including the location of close-ups in the retinal pigmented epithelial layer (a), photoreceptor cell layer (b), nuclear layer (c) and ganglion cell layer (d). Scale bar: 100 µm. Retinal pigmented epithelial layer (a): Fzd3, Alcam or Pax2 deficient eyes show thicker RPE layers. Photoreceptor cell layer (b): In Control MO injected embryos, the photoreceptor cell layer mainly includes photoreceptor cells, which are embedded in the retinal-pigmented epithelium (RPE). RPE cells contain melanin granuli (mg), photoreceptors specific membrane stacks (ms). Selected photoreceptor cells are highlighted by dotted circles. Upon Fzd3, Alcam or Pax2 depletion, intercellular spaces (ICS) are increased leading to detachment of photoreceptors (red arrowhead). Nuclear layer (c): The natural nuclear cell layer (NCL) of Control MO injected eyes is characterized by retina-specific cell nuclei such as nuclei of bipolar (BC), amacrine (AC) and photoreceptor cells (PRN). In contrast, the NCL of Fzd3, Alcam and Pax2 morphants was disorganized by the formation of rosette-like structures characterized by membrane stacks (ms) indicating ectopic photoreceptor cells. Moreover, Fzd3 and Alcam MO injection leads to an increase of intercellular spaces (ICS), an indication for cell adhesion defects. Ganglion cell layer (d): Ganglions are normally differentiated in Control, Fzd3, Alcam or Pax2 MO injected retinas. Scale bar: 5000 nm. Abbreviations: AC, amacrine cell; BC, bipolar cell; ICS, intercellular space; NF, neuronal fiber; RPE, retinal pigmented epithelium; mg, melanin granula; ms, membrane stacks; PRN, photoreceptor nucleus. Number of embryos analyzed by TEM: Control MO, 9; Fzd3 MO, 4; Alcam MO, 4; Pax2 MO, 4. Image published in: Seigfried FA et al. (2017) Copyright © 2017. Image reproduced with permission of the Publisher, Elsevier B. V. Larger Image Printer Friendly View

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