File:Retinal patterning model.jpg

Model for retinal patterning and morphogenesis along the nasal-temporal axis (Zebrafish)

(A) Schematic cross-section, illustrating nasal-temporal pattern formation during optic vesicle and optic cup morphogenesis. Fgf8/3/24-dependent axis specification occurs along the dorsal-ventral axis of the optic vesicle (left). Initially, only nasal retina progenitors (green) populate the future neural retina domain. During optic cup formation, temporal progenitor cell movements (red) lead to axis reorientation (middle). In parallel, the eye rotates anteriorly. Together, these movements result in the anterior-posterior alignment of the nasal-temporal retina axis (right).

(B) Directed, late movement of foxd1-expressing, temporal progenitors (red) around the distal ridge into the outer optic cup layer and gradual displacement of foxg1-expressing nasal progenitors (green) leads to the final nasal-temporal subdivision of the definitive neural retina domain in the outer optic cup layer (white dotted line). In the absence of Fgf8/3/24, misspecified (foxg1-negative/foxd1-positive) retinal progenitors in the presumptive nasal region (green) delaminate, and temporal progenitors (red) show increased cell movements into the outer optic cup layer.

(C) Effect of Fgf signaling on cell cohesion and morphogenesis. Fgf8/3/24 are first required for foxg1 gene expression in nasal retina progenitors. Foxg1 protein enhances cell cohesion in the presence of Fgfs through an unknown feed-forward mechanism. The resulting retention of Foxg1-expressing cells at sites of Fgf signaling enhances the feed-forward effect.

a, anterior; d, dorsal; l, lateral; m, medial; n, nasal; olf, olfactory placode; p, posterior; t, temporal; v, ventral.

Original file name: Figure 8. doi:10.1371/journal.pbio.1000214.g008

Reference

<pubmed>19823566</pubmed>| PMC2751823 | PLoS Biol

Picker A, Cavodeassi F, Machate A, Bernauer S, Hans S, et al. (2009) Dynamic Coupling of Pattern Formation and Morphogenesis in the Developing Vertebrate Retina. PLoS Biol 7(10): e1000214. doi:10.1371/journal.pbio.1000214

Copyright: © 2009 Picker et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.