The Msh-like homeobox genes define domains in the developing vertebrate eye

Development ◽  
1991 ◽  
Vol 112 (4) ◽  
pp. 1053-1061 ◽  
Author(s):  
A.P. Monaghan ◽  
D.R. Davidson ◽  
C. Sime ◽  
E. Graham ◽  
R. Baldock ◽  
...  
Keyword(s):  
Mouse Embryo ◽  
Ciliary Body ◽  
Cellular Differentiation ◽  
Temporal Relationship ◽  
Chromosomal Location ◽  
Neural Retina ◽  
Optic Vesicle ◽  
Surface Ectoderm ◽  
Optic Cup ◽  
Vertebrate Eye

The mouse Hox-7.1 gene has previously been shown to be related to the Drosophila Msh homeobox-containing gene. Here we report the isolation of a new member of this family which resides at an unlinked chromosomal location and has been designated Hox-8.1. Both Hox-7.1 and Hox-8.1 are expressed in the mouse embryo during the early stages of eye development in a distinct spatial and temporal relationship. Hox-8.1 is expressed in the surface ectoderm and in the optic vesicle before invagination occurs in regions corresponding to the prospective corneal epithelium and neural retina, respectively. Hox-7.1 is expressed after formation of the optic cup, marking the domain that will give rise to the ciliary body. The activity of these genes indicates that the inner layer of the optic cup is differentiated into three distinct compartments before overt cellular differentiation occurs. Our results suggest that these genes are involved in defining the region that gives rise to the inner layer of the optic cup and in patterning this tissue to define the iris, ciliary body and retina.

Extraocular mesenchyme patterns the optic vesicle during early eye development in the embryonic chick

Development ◽  
2000 ◽  
Vol 127 (21) ◽  
pp. 4599-4609 ◽  
Author(s):  
S. Fuhrmann ◽  
E.M. Levine ◽  
T.A. Reh
Keyword(s):  
Matrix Protein ◽  
Eye Development ◽  
Neural Retina ◽  
Optic Vesicle ◽  
Lateral Plate ◽  
Surface Ectoderm ◽  
Eye Growth ◽  
Pigmented Epithelium ◽  
Optic Vesicles ◽  
Vertebrate Eye

The vertebrate eye develops from the neuroepithelium of the ventral forebrain by the evagination and formation of the optic vesicle. Classical embryological studies have shown that the surrounding extraocular tissues - the surface ectoderm and extraocular mesenchyme - are necessary for normal eye growth and differentiation. We have used explant cultures of chick optic vesicles to study the regulation of retinal pigmented epithelium (RPE) patterning and differentiation during early eye development. Our results show that extraocular mesenchyme is required for the induction and maintenance of expression of the RPE-specific genes Mitf and Wnt13 and the melanosomal matrix protein MMP115. In the absence of extraocular tissues, RPE development did not occur. Replacement of the extraocular mesenchyme with cranial mesenchyme, but not lateral plate mesoderm, could rescue expression of the RPE-marker Mitf. In addition to activating expression of RPE-specific genes, the extraocular mesenchyme inhibits the expression of the neural retina-specific transcription factor Chx10 and downregulates the eye-specific transcription factors Pax6 and Optx2. The TGF(β) family member activin can substitute for the extraocular mesenchyme by promoting expression of the RPE-specific genes and downregulating expression of the neural retina-specific markers. These data indicate that extraocular mesenchyme, and possibly an activin-like signal, pattern the domains of the optic vesicle into RPE and neural retina.

Patterning the Vertebrate Retina with Morphogenetic Signaling Pathways

2019 ◽  
Vol 26 (2) ◽  
pp. 185-196 ◽  
Author(s):  
Marcos J. Cardozo ◽  
María Almuedo-Castillo ◽  
Paola Bovolenta
Keyword(s):  
Signaling Pathways ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Subsequent Development ◽  
Neural Retina ◽  
Bmp Signaling ◽  
Vertebrate Species ◽  
Optic Stalk ◽  
Optic Cup ◽  
Vertebrate Eye

The primordium of the vertebrate eye is composed of a pseudostratified and apparently homogeneous neuroepithelium, which folds inward to generate a bilayered optic cup. During these early morphogenetic events, the optic vesicle is patterned along three different axes—proximo-distal, dorso-ventral, and naso-temporal—and three major domains: the neural retina, the retinal pigment epithelium (RPE), and the optic stalk. These fundamental steps that enable the subsequent development of a functional eye, entail the precise coordination among genetic programs. These programs are driven by the interplay of signaling pathways and transcription factors, which progressively dictate how each tissue should evolve. Here, we discuss the contribution of the Hh, Wnt, FGF, and BMP signaling pathways to the early patterning of the retina. Comparative studies in different vertebrate species have shown that their morphogenetic activity is repetitively used to orchestrate the progressive specification of the eye with evolutionary conserved mechanisms that have been adapted to match the specific need of a given species.

scholarly journals Epithelial flow into the optic cup facilitated by suppression of BMP drives eye morphogenesis

2014 ◽  
Author(s):  
Stephan Heermann ◽  
Lucas Schuetz ◽  
Steffen Lemke ◽  
Kerstin Krieglstein ◽  
Joachim Wittbrodt
Keyword(s):  
Morphological Changes ◽  
Fold Increase ◽  
Optic Vesicle ◽  
Retinal Pigmented Epithelium ◽  
Basal Surface ◽  
Classical View ◽  
Optic Cup ◽  
Pigmented Epithelium ◽  
Vertebrate Eye ◽  
Eye Morphogenesis

The transformation of the oval optic vesicle to a hemispheric bi-layered optic cup involves major morphological changes during early vertebrate eye development. According to the classical view, the lens-averted epithelium differentiates into the retinal pigmented epithelium (RPE), while the lens-facing epithelium forms the neuroretina. We find a 4.7 fold increase of the entire basal surface of the optic cup. Although the area an individual RPC demands at its basal surface declines during optic cup formation, we find a 4.7 fold increase of the entire basal surface of the optic cup. We demonstrate that the lens-averted epithelium functions as reservoir and contributes to the growing neuroretina by epithelial flow around the distal rims of the optic cup. This flow is negatively modulated by BMP, which arrests epithelial flow. This inhibition results in persisting neuroretina in the RPE domain and ultimately in coloboma.

scholarly journals Eye morphogenesis driven by epithelial flow into the optic cup facilitated by modulation of bone morphogenetic protein

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Stephan Heermann ◽  
Lucas Schütz ◽  
Steffen Lemke ◽  
Kerstin Krieglstein ◽  
Joachim Wittbrodt
Keyword(s):  
Marginal Zone ◽  
Eye Development ◽  
Optic Vesicle ◽  
Basal Surface ◽  
Morphogenetic Protein ◽  
Retinal Determination ◽  
Optic Cup ◽  
Morphological Transformations ◽  
Vertebrate Eye ◽  
Ciliary Marginal Zone

The hemispheric, bi-layered optic cup forms from an oval optic vesicle during early vertebrate eye development through major morphological transformations. The overall basal surface, facing the developing lens, is increasing, while, at the same time, the space basally occupied by individual cells is decreasing. This cannot be explained by the classical view of eye development. Using zebrafish (Danio rerio) as a model, we show that the lens-averted epithelium functions as a reservoir that contributes to the growing neuroretina through epithelial flow around the distal rims of the optic cup. We propose that this flow couples morphogenesis and retinal determination. Our 4D data indicate that future stem cells flow from their origin in the lens-averted domain of the optic vesicle to their destination in the ciliary marginal zone. BMP-mediated inhibition of the flow results in ectopic neuroretina in the RPE domain. Ultimately the ventral fissure fails to close resulting in coloboma.

Mechanics of Optic Cup Invagination in the Embryonic Chick Eye

2012 ◽  
Author(s):  
Alina Oltean ◽  
David C. Beebe ◽  
Larry A. Taber
Keyword(s):  
Eye Development ◽  
Embryonic Chick ◽  
Optic Vesicle ◽  
Surface Ectoderm ◽  
Morphogenetic Process ◽  
Optic Cup ◽  
Optic Vesicles ◽  
Lens Vesicle ◽  
Lens Placode

Invagination of epithelia is an essential morphogenetic process that occurs in early eye development. The mechanics of the tissue forces necessary for eye invagination are not yet understood [1]. The eyes begin as two optic vesicles that grow outwards from the forebrain and adhere to the surface ectoderm. At this point of contact, both the surface ectoderm and optic vesicle thicken, forming the lens placode and retinal placode, respectively. The two placodes then bend inward to create the lens vesicle and bilayered optic cup (OC) [1, 2].

scholarly journals Stretching of the retinal pigment epithelium contributes to zebrafish optic cup morphogenesis

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Tania Moreno-Mármol ◽  
Mario Ledesma-Terrón ◽  
Noemi Tabanera ◽  
Maria Jesús Martin-Bermejo ◽  
Marcos J Cardozo ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Neural Retina ◽  
Efficient Solutions ◽  
Mechanical Forces ◽  
Rpe Cells ◽  
Virtual Absence ◽  
Optic Cup ◽  
Vertebrate Eye

The vertebrate eye-primordium consists of a pseudostratified neuroepithelium, the optic vesicle (OV), in which cells acquire neural retina or retinal pigment epithelium (RPE) fates. As these fates arise, the OV assumes a cup-shape, influenced by mechanical forces generated within the neural retina. Whether the RPE passively adapts to retinal changes or actively contributes to OV morphogenesis remains unexplored. We generated a zebrafish Tg(E1-bhlhe40:GFP) line to track RPE morphogenesis and interrogate its participation in OV folding. We show that, in virtual absence of proliferation, RPE cells stretch and flatten, thereby matching the retinal curvature and promoting OV folding. Localized interference with the RPE cytoskeleton disrupts tissue stretching and OV folding. Thus, extreme RPE flattening and accelerated differentiation are efficient solutions adopted by fast-developing species to enable timely optic cup formation. This mechanism differs in amniotes, in which proliferation drives RPE expansion with a much-reduced need of cell flattening.

scholarly journals Meis homeobox genes control progenitor competence in the retina

2021 ◽  
Vol 118 (12) ◽  
pp. e2013136118
Author(s):  
Naoko Dupacova ◽  
Barbora Antosova ◽  
Jan Paces ◽  
Zbynek Kozmik
Keyword(s):  
Cell Fate ◽  
Homeobox Genes ◽  
Spatial Separation ◽  
Optic Disk ◽  
Surface Ectoderm ◽  
Genetic Ablation ◽  
Retinal Progenitor ◽  
Expression Of Genes ◽  
Optic Cup ◽  
Vertebrate Eye

The vertebrate eye is derived from the neuroepithelium, surface ectoderm, and extracellular mesenchyme. The neuroepithelium forms an optic cup in which the spatial separation of three domains is established, namely, the region of multipotent retinal progenitor cells (RPCs), the ciliary margin zone (CMZ)—which possesses both a neurogenic and nonneurogenic potential—and the optic disk (OD), the interface between the optic stalk and the neuroretina. Here, we show by genetic ablation in the developing optic cup that Meis1 and Meis2 homeobox genes function redundantly to maintain the retinal progenitor pool while they simultaneously suppress the expression of genes characteristic of CMZ and OD fates. Furthermore, we demonstrate that Meis transcription factors bind regulatory regions of RPC-, CMZ-, and OD-specific genes, thus providing a mechanistic insight into the Meis-dependent gene regulatory network. Our work uncovers the essential role of Meis1 and Meis2 as regulators of cell fate competence, which organize spatial territories in the vertebrate eye.

scholarly journals Stretching of the retinal pigment epithelium contributes to zebrafish optic cup morphogenesis

2020 ◽  
Author(s):  
Tania Moreno-Mármol ◽  
Mario Ledesma-Terrón ◽  
Noemí Tabanera ◽  
María Jesús Martin-Bermejo ◽  
Marcos J Cardozo ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Neural Retina ◽  
Efficient Solutions ◽  
Mechanical Forces ◽  
Rpe Cells ◽  
Virtual Absence ◽  
Optic Cup ◽  
Vertebrate Eye

AbstractThe vertebrate eye primordium consists of a pseudostratified neuroepithelium, the optic vesicle (OV), in which cells acquire neural retina or retinal pigment epithelium (RPE) fates. As these fates arise, the OV assumes a cup-shape, influenced by mechanical forces generated within the neural retina. Whether the RPE passively adapts to retinal changes or actively contributes to OV morphogenesis remains unexplored. Here, we generated a zebrafish Tg(E1-bhlhe40:GFP) line to track RPE morphogenesis and interrogate its participation in OV folding. We show that, in virtual absence of proliferation, RPE cells stretch into a squamous configuration, thereby matching the curvature of the underlying retina. Forced proliferation and localized interference with the RPE cytoskeleton disrupt its stretching and OV folding. Thus, extreme RPE flattening and accelerated differentiation are efficient solutions adopted by fast-developing species to enable timely optic cup formation. This mechanism differs in amniotes, in which proliferation largely drives RPE expansion with a much-reduced need of cell flattening.

FGF1 patterns the optic vesicle by directing the placement of the neural retina domain

Development ◽  
1998 ◽  
Vol 125 (5) ◽  
pp. 869-877 ◽  
Author(s):  
J. Hyer ◽  
T. Mima ◽  
T. Mikawa
Keyword(s):  
Neural Retina ◽  
Expression Vectors ◽  
Expression Data ◽  
Optic Vesicle ◽  
Surface Ectoderm ◽  
Pigmented Epithelium ◽  
Optic Vesicles ◽  
Cell Phenotypes

Patterning of the bipotential retinal primordia (the optic vesicles) into neural retina and retinal pigmented epithelium depends on its interaction with overlaying surface ectoderm. The surface ectoderm expresses FGFs and the optic vesicles express FGF receptors. Previous FGF-expression data and in vitro analyses support the hypothesis that FGF signaling plays a significant role in patterning the optic vesicle. To test this hypothesis in vivo we removed surface ectoderm, a rich source of FGFs. This ablation generated retinas in which neural and pigmented cell phenotypes were co-mingled. Two in vivo protocols were used to replace FGF secretion by surface ectoderm: (1) implantation of FGF-secreting fibroblasts, and (2) injection of replication-incompetent FGF retroviral expression vectors. The retinas in such embryos exhibited segregated neural and pigmented epithelial domains. The neural retina domains were always close to a source of FGF secretion. These results indicate that, in the absense of surface ectoderm, cells of the optic vesicles display both neural and pigmented retinal phenotypes, and that positional cues provided by FGF organize the bipotential optic vesicle into specific neural retina and pigmented epithelium domains. We conclude that FGF can mimic one of the earliest functions of surface ectoderm during eye development, namely the demarcation of neural retina from pigmented epithelium.

scholarly journals Build me up optic cup: Intrinsic and extrinsic mechanisms of vertebrate eye morphogenesis

2021 ◽  
Vol 476 ◽  
pp. 128-136
Author(s):  
Macaulie A. Casey ◽  
Sarah Lusk ◽  
Kristen M. Kwan
Keyword(s):  
Optic Cup ◽  
Vertebrate Eye ◽  
Eye Morphogenesis
Sign in / Sign up

Export Citation Format

Share Document