The effect of inhibitors of glycoconjugate synthesis on optic cup formation in the chick embryo

Yang, Jyh-Jia W.; Hilfer, S. Robert

doi:10.1016/0012-1606(82)90148-8

Cited by 19 publications

(8 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is interesting to note that the lack of invagination of the retinal disc is not always associated with that of the lens placode. This fact emphasizes the idea that the two processes of epithelia1 invagination appear to be regulated by a different set of factors (Coulombre, 1965;Maloney and Wakely, 1982a,b;Yang and Hilfer, 1982). Dorsoventral asymmetry of the lens cup is a normal feature of the developing chick lens (Wakely, 1976;Bancroft and Bellairs, 1977;.…”

Section: Discussionmentioning

confidence: 77%

Retinal cell death occurs in the absence of retinal disc invagination: Experimental evidence in papaverine‐treated chicken embryos

1987

View full text Add to dashboard Cite

In an attempt to clarify the relationship between the presence of retinal cell death and the invagination of the optic vesicle, we have tested the occurrence and cytological characteristics of the retinal necrotic areas in the embryonic chicken after the administration in ovo of papaverine. Papaverine, a Ca2+ antagonist, was found to prevent the invagination of the optic vesicle. All embryonic retinae presented two distinct necrotic areas. However, these areas of cell death appeared abnormally located in the experimental, uninvaginated retina. One area was located at the transition between the retinal disc and the ventral wall of the optic vesicle; a second area was located in the dorsal wall of the optic vesicle, close to the optic stalk. We suggest that these necrotic areas represent the normal necrotic areas, should the invagination of the retinal disc have taken place. Retinal cell death appears to be programmed; it occurs whether the retinal disc invaginates or not. Cell death appears, in this experimental model, as a natural marker giving evidence that the embryonic retinal cells move from the optic stalk into the invagination retinal disc during normal eye cup formation. In addition to the uninvaginated optic vesicle the lens placode failed to invaginate in 45% of the cases, forming a lens vesicle in 55% of the remaining cases. This suggests that the two processes of invagination are governed by a different set of factors.

show abstract

Section: Discussionmentioning

confidence: 77%

Retinal cell death occurs in the absence of retinal disc invagination: Experimental evidence in papaverine‐treated chicken embryos

1987

View full text Add to dashboard Cite

show abstract

“…Moreover, it was shown that, in Aphakic strain mice with alterations in the composition of the apical`cell coat' glycosaminoglycans there are serious defects in early lens development (Zwaan and Webster, 1984). It is not known how these covering glycoconjugates are able to intervene in epithelial invagination, although it has been suggested that these molecules may bind and concentrate large amounts of Ca near the apical surface of the above-mentioned cells and activate contraction of the apical micro®laments involved in cell form changes (Yang and Hilfer, 1982;Slepecky and Chamberlain, 1985;Turley, Brassel and Moore, 1990). In addition, the presence of intense CSPG immunomarking on the basal lamina of the lens primordium during the entire study period has been demonstrated.…”

Section: Discussionmentioning

confidence: 99%

Chondroitin Sulphate Proteoglycan is Involved in Lens Vesicle Morphogenesis in Chick Embryos

Gato

Martín

Alonso

et al. 2001

Experimental Eye Research

View full text Add to dashboard Cite

Proteoglycans have been implicated in the invagination and formation of various embryonal cavitied primordia. In this paper the expression of chondroitin sulphate proteoglycan is analysed (CSPG) in the lens primordium during lens vesicle formation, and demonstrate that this proteoglycan has a speci®c distribution pattern with regard to invagination and fusion processes in the transformation of placode into lens vesicle. More speci®cally, CSPG was detached in: (1) the apical surface of lens epithelial cells, where early CSPG expression was observed in the whole of the lens placode whilst in the vesicle phase it was restricted to the posterior epithelium; (2) intense CSPG expression in the basal lamina, which remained constant for the entire period under study; (3) CSPG expression in the intercellular spaces of the lens primordium epithelium, which increased during the invagination of the primordium and which at the vesicle stage was more evident in the posterior epithelium; and (4) CSPG expression on the edges of the lens placode both prior to and during fusion. Treatment with b-D-xyloside causes signi®cant CSPG depletion in the lens primordium together with severe alterations in the invagination and fusion of the lens vesicle; this leads to the formation of lens primordia which in some cases remain practically¯at or show partial invagination defects or fusion disruption. Similar results were obtained by enzyme digestion with chondroitinase AC but not with type II heparinase, which indicates that alterations induced by b-Dxyloside were due to interference in CSPG synthesis. The ®ndings demonstrate that CSPG is a common component of the lens primordium at the earliest developmental stages during which it undergoes speci®c modi®cations. It also includes experimental evidence to show that`in vivo' CSPG plays an important role in the invagination and fusion processes of the lens primordium.

show abstract

“…These studies resulted in reduced fusion of the neural folds and palatal shelves, respectively. In addition, inhibitors of glycoconjugate synthesis including 6diazo-5-0x0-L-norleucine, tunicamycin, and carrageenan have been shown to produce facial clefts (Burk and Sadler, 1983), neural tube defects (Rovasio and Monis, 19811, reduced fusion of palatal shelves in vitro (Greene and Pratt, 1977), and abnormal optic cup formation (Yang and Hilfer, 1982).…”

Section: Discussionmentioning

confidence: 99%

Surface coat material associated with the developing otic placode/vesicle in the chick

Sinning

Olson

1988

Anat. Rec.

View full text Add to dashboard Cite

Surface coat material (SCM) has been illustrated in association with the apical surfaces of numerous epithelia during morphogenesis. This study investigates the development of a SCM associated with the invaginating otic placode/vesicle in the chick. Glycoconjugate containing SCM was retained by the inclusion of cetylpyridinium chloride (CPC) in the fixative, histochemically visualized by using ruthenium red (RR) staining, and viewed by scanning (SEM) or transmission (TEM) electron microscopy. Initial characterization of the glycoconjugates present in this material was elucidated by using lectins conjugated to fluorescein isothiocyanate. Lectins utilized included concanavalin A (Con A), wheat germ agglutinin (WGA), and soybean agglutinin (SBA). Invagination of the otic placode was apparent as early as stage 12. By stage 15 the vesicle was beginning to separate from the surface ectoderm as evidenced by its aperture, which was altered in shape and reduced in size. All embryos fixed with glutaraldehyde containing either CPC or RR were shown to possess SCM associated with the surface ectoderm, particularly in the area of the otic placode/vesicle. Additional embryos were processed by cryofixation without prior aldehyde fixation; these also exhibited SCM. All lectins labelled the epithelium of the otic placode/vesicle. However, their binding patterns were not identical. The binding of Con A and WGA remained constant over the stages studied, while SBA increased as the otic vesicle developed. The data clearly indicate that otic placode morphogenesis is accompanied by the synthesis of SCM rich in glycoconjugates.

show abstract

The effect of inhibitors of glycoconjugate synthesis on optic cup formation in the chick embryo

Cited by 19 publications

References 39 publications

Retinal cell death occurs in the absence of retinal disc invagination: Experimental evidence in papaverine‐treated chicken embryos

Retinal cell death occurs in the absence of retinal disc invagination: Experimental evidence in papaverine‐treated chicken embryos

Chondroitin Sulphate Proteoglycan is Involved in Lens Vesicle Morphogenesis in Chick Embryos

Surface coat material associated with the developing otic placode/vesicle in the chick

Contact Info

Product

Resources

About