A critical role for the optic vesicle in lens development; A reinvestigation of free lens formation in

1998 ◽  
Vol 63 (5) ◽  
pp. 247
Author(s):  
Nobuhiko Mizuno ◽  
Makoto Mochii ◽  
Chiyo Takagi ◽  
T. C. Takahashi ◽  
Goro Eguchi ◽  
...  
Keyword(s):  
Critical Role ◽  
Optic Vesicle ◽  
Lens Development ◽  
Lens Formation

A critical role for the optic vesicle in lens development; A reinvestigation of free lens formation in Cynops pyrrhogaster

1998 ◽  
Vol 63 (5) ◽  
pp. 247-252 ◽  
Author(s):  
Nobuhiko Mizuno ◽  
Tadashi C. Takahashi ◽  
T.S. Okada ◽  
Makoto Mochii ◽  
Chiyo Takagi ◽  
...  
Keyword(s):  
Critical Role ◽  
Optic Vesicle ◽  
Lens Development ◽  
Cynops Pyrrhogaster ◽  
Lens Formation

scholarly journals A Potential Role for MMPs during the Formation of Non-Neurogenic Placodes

2018 ◽  
Vol 6 (3) ◽  
pp. 20 ◽  
Author(s):  
Paige Drake ◽  
Tamara Franz-Odendaal
Keyword(s):  
Extracellular Matrix ◽  
Mammary Gland ◽  
Matrix Metalloproteinases ◽  
Potential Role ◽  
Critical Role ◽  
Extracellular Matrix Remodeling ◽  
Matrix Remodeling ◽  
Lens Development ◽  
Cell Behaviors ◽  
Placode Formation

The formation of non-neurogenic placodes is critical prior to the development of several epithelial derivatives (e.g., feathers, teeth, etc.) and their development frequently involves morphogenetic proteins (or morphogens). Matrix metalloproteinases (MMPs) are important enzymes involved in extracellular matrix remodeling, and recent research has shown that the extracellular matrix (ECM) can modulate morphogen diffusion and cell behaviors. This review summarizes the known roles of MMPs during the development of non-neurogenic structures that involve a placodal stage. Specifically, we discuss feather, hair, tooth, mammary gland and lens development. This review highlights the potential critical role MMPs may play during placode formation in these systems.

Permissive and directive interactions in lens induction

Development ◽  
1978 ◽  
Vol 44 (1) ◽  
pp. 167-179
Author(s):  
Marketta Karkinen-Jääskeläinen
Keyword(s):  
Culture Conditions ◽  
Chick Embryos ◽  
Optic Vesicle ◽  
Lens Proteins ◽  
Lens Formation

The interactive events leading to lens formation and the developmental potentialities of the presumptive lens ectoderm were examined in vitro. The presumptivelens ectoderm of both mouse and chick embryos was capable of forming a lens even when isolated from the optic vesicle before the two tissues reach the stage of close association.This lens-forming bias can be released with favourable culture conditions and by various heterotypic mesenchymes. The same permissive, unspecific conditions or heterotypic tissues failed to trigger lens formation in trunk ectoderm. The directive effect of the optic vesicle was demonstrated in experiments where it was grown in contact with the trunk ectoderm. The latter developed distinct lentoid bodies synthesizing lens proteins. The origin of the lentoid was confirmed in interspecies combination of chick and quail tissues. Itis concluded that lens formation is governed by a series of interactive events consisting of both directive and permissive influences.

Pax6 is required for establishing naso-temporal and dorsal characteristics of the optic vesicle

Development ◽  
2002 ◽  
Vol 129 (19) ◽  
pp. 4535-4545 ◽  
Author(s):  
Nicole Bäumer ◽  
Till Marquardt ◽  
Anastassia Stoykova ◽  
Ruth Ashery-Padan ◽  
Kamal Chowdhury ◽  
...  
Keyword(s):  
Ganglion Cells ◽  
Eye Development ◽  
Genetic Network ◽  
Axis Formation ◽  
Pax6 Gene ◽  
Optic Vesicle ◽  
Intronic Enhancer ◽  
Key Factor ◽  
Lens Formation

The establishment of polarity is an important step during organ development. We assign a function for the paired and homeodomain transcription factor Pax6 in axis formation in the retina. Pax6 is a key factor of the highly conserved genetic network implicated in directing the initial phases of eye development. We recently demonstrated that Pax6 is also essential for later aspects of eye development, such as lens formation and retinogenesis. In this study, we present evidence that a highly conserved intronic enhancer, α, in the Pax6 gene is essential for the establishment of a distalhigh-proximallow gradient of Pax6 activity in the retina. In the mature retina, the activity mediated by the α-enhancer defines a population of retinal ganglion cells that project to two sickle-shaped domains in the superior colliculus and lateral geniculate nucleus. Deletion of the α-enhancer in vivo revealed that retinal Pax6 expression is regulated in two complementary topographic domains. We found that Pax6 activity is required for the establishment, as well as the maintenance of dorsal and nasotemporal characteristics in the optic vesicle and, later, the optic cup.

A reinvestigation of some of the tissue movements involved in the formation of the neural tube and the eye/lens system of Triturus alpestris and Xenopus laevis

Development ◽  
1966 ◽  
Vol 16 (3) ◽  
pp. 431-438
Author(s):  
R. S. Lowery
Keyword(s):  
Xenopus Laevis ◽  
Neural Tube ◽  
Subsequent Development ◽  
Neural Plate ◽  
Eye Lens ◽  
Optic Vesicle ◽  
Lens System ◽  
Lens Development ◽  
Triturus Alpestris ◽  
Optic Cup

Since the beginning of the century the generally accepted scheme of eye/lens development has been that proposed by Spemann (1901) and later confirmed by numerous workers. According to this scheme the two presumptive components of the definitive eye, the optic cup and the lens, are spatially separated at the flat neural plate stage. They later come into apposition as a result of tissue movements which occur during the formation of the neural tube; the optic vesicle then provides an inductive stimulus for the subsequent development of the presumptive lens tissue. Spemann's suggestions concerning the tissue movements involved in the early formation of the eye/lens system do not appear to have been fundamentally questioned until the publication of a number of papers by Chanturishvili (1943, 1949,1958,1959,1962), although the theory of lens induction has been modified by workers such as Liedke (1955), Jacobson (1963) and von Woellwarth (1962).

Reinvestigation of the role of the optic vesicle in embryonic lens induction

Development ◽  
1988 ◽  
Vol 102 (3) ◽  
pp. 517-526 ◽  
Author(s):  
R.M. Grainger ◽  
J.J. Herry ◽  
R.A. Henderson
Keyword(s):  
Xenopus Laevis ◽  
Optic Vesicle ◽  
Multistep Process ◽  
Optic Vesicles ◽  
Original Report ◽  
Lens Formation ◽  
Embryonic Ectoderm ◽  
Transplantation Experiments ◽  
Xenopus Laevis Embryos

The induction of the lens by the optic vesicle in amphibians is often cited as support for the view that a single inductive event can lead to determination in a multipotent tissue. This conclusion is based on transplantation experiments whose results indicate that many regions of embryonic ectoderm which would normally form epidermis can form a lens if brought into contact with the optic vesicle. Although additional evidence argues that during normal development other tissues, acting before the optic vesicle, also contribute to lens induction, it is still widely held, on the basis of these transplantation experiments, that the optic vesicle alone can elicit lens formation in ectoderm. While testing this conclusion by transplanting optic vesicles beneath ventral ectoderm in Xenopus laevis embryos, it became apparent that contamination of optic vesicles by presumptive lens ectoderm cells can generate lenses in these experiments, illustrating the need for adequate host and donor marking procedures. Since previous studies rarely used host and donor marking, it was not clear whether they actually demonstrated that the optic vesicle can induce lenses. Using careful host and donor marking procedures with horseradish peroxidase as a lineage tracer, we show that the optic vesicle cannot stimulate lens formation in neurula- or gastrula-stage ectoderm of Xenopus laevis. Since the general conclusion that the optic vesicle is sufficient for lens induction rests on studies in many organisms, we felt it was important to begin to test this conclusion in other amphibians as well. Similar experiments were therefore performed with Rana Palustris embryos, since it was in this organism that optic vesicle transplant studies had originally argued that this tissue alone can cause lens induction. Under conditions similar to those used in the original report, but with careful controls to assess the origin of lenses in transplants, we found that the optic vesicle alone cannot elicit lens formation. Our data lead us to propose that the optic vesicle in amphibians is not generally sufficient for lens induction. Instead, we argue that lens induction occurs by a multistep process in which an essential phase in lens determination occurs as a result of inductive interactions preceding contact of ectoderm with the optic vesicle.

scholarly journals The lens: a classical model of embryonic induction providing new insights into cell determination in early development

2011 ◽  
Vol 366 (1568) ◽  
pp. 1193-1203 ◽  
Author(s):  
Lena Gunhaga
Keyword(s):  
Molecular Interactions ◽  
Classical Model ◽  
Embryonic Induction ◽  
Optic Vesicle ◽  
Progressive Development ◽  
Signalling Molecules ◽  
Tissue Interactions ◽  
Lens Formation ◽  
Lens Placode ◽  
Shed Light

The lens was the first tissue in which the concept of embryonic induction was demonstrated. For many years lens induction was thought to occur at the time the optic vesicle and lens placode came in contact. Since then, studies have revealed that lens placodal progenitor cells are specified already at gastrula stages, much earlier than previously believed, and independent of optic vesicle interactions. In this review, I will focus on how individual signalling molecules, in particular BMP, FGF, Wnt and Shh, regulate the initial specification of lens placodal cells and the progressive development of lens cells. I will discuss recent work that has shed light on the combination of signalling molecules and the molecular interactions that affect lens specification and proper lens formation. I will also discuss proposed tissue interactions important for lens development. A greater knowledge of the molecular interactions during lens induction is likely to have practical benefits in understanding the causes and consequences of lens diseases. Moreover, knowledge regarding lens induction is providing fundamental important insights into inductive processes in development in general.

scholarly journals Growth and Cellular Proliferation in the Early Rudiments of the Eye and the Lens

1952 ◽  
Vol s3-93 (23) ◽  
pp. 357-368
Author(s):  
B. I. BALINSKY
Keyword(s):  
Xenopus Laevis ◽  
Mitotic Index ◽  
Cellular Proliferation ◽  
Lens Development ◽  
Morphogenetic Movements ◽  
Duration Of Mitosis ◽  
Morphogenetic Movement ◽  
The Future ◽  
Lens Formation ◽  
Lens Material

1. The relation between growth, cellular proliferation, and morphogenetic movements was investigated in the case of lens formation in Elephantulus myurus jamesoni and Xenopus laevis. 2. For this purpose the volume of the eye cup and lens rudiments was estimated, counts of cells were made, and at the same time counts of cells in mitosis. The mitotic index was calculated, and the material wherever possible was treated statistically. 3. The lens rudiment grows at a greater rate than the eye cup rudiment during the stages in which the lens is being formed. The rate of cellular proliferation in the lens rudiment is also higher than in the eye cup rudiment. The size of the lens cells remains constant whilst the size of the eye cup cells diminishes during the period investigated (at least in Xenopus). 4. The mitotic index in the lens material is lower than in the eye cup material. This indicates that the duration of mitosis in relation to the interkinetic period is, in the eye cup rudiment, greater than in the lens rudiment. 5. The mitotic index in the lens material does not increase or decrease significantly during any stage of the lens development, nor were there found any other indications of an increased or decreased growth or proliferation of the lens material. It is therefore concluded that the formation of a visible lens rudiment is due to morphogenetic movement--contraction of a sheet of cells towards the centre of the future eye cup.

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