scholarly journals Composition, Synthesis, and Assembly of the Embryonic Chick Retinal Basal Lamina

2000 ◽  
Vol 220 (2) ◽  
pp. 111-128 ◽  
Author(s):  
W. Halfter ◽  
S. Dong ◽  
B. Schurer ◽  
A. Osanger ◽  
W. Schneider ◽  
...  
Keyword(s):  
Basal Lamina ◽  
Embryonic Chick

Expression of basal lamina protein mRNAs in the early embryonic chick eye

2002 ◽  
Vol 447 (3) ◽  
pp. 261-273 ◽  
Author(s):  
Sucai Dong ◽  
Jeffry Landfair ◽  
Manimalha Balasubramani ◽  
Mark E. Bier ◽  
Greg Cole ◽  
...  
Keyword(s):  
Basal Lamina ◽  
Embryonic Chick

Antisera to basal lamina and glial endfeet disturb the normal extension of axons on retina and pigment epithelium basal laminae

Development ◽  
1989 ◽  
Vol 107 (2) ◽  
pp. 281-297
Author(s):  
W. Halfter
Keyword(s):  
Basal Lamina ◽  
Pigment Epithelium ◽  
Growth Cones ◽  
Normal Extension ◽  
Embryonic Chick ◽  
Adhesive Matrix ◽  
Chick Retina ◽  
Directed Growth ◽  
The Individual

In order to determine the role of the extracellular matrix in regulating the directed growth of embryonic neurites, antisera to retina (a-RBL I and II), to pigment epithelium (a-PBL) and to glomerular (a-GBL) basal lamina were probed for an effect on the ordered extension of neurites. In the assays, retina explants from chick and quail were cultured on basal lamina from embryonic chick retina and pigment epithelium either in the presence of anti-basal lamina antisera or in the presence of the corresponding preimmune sera. In the presence of all anti-basal lamina antisera, normal extension of axons was greatly inhibited both on retina and on pigment epithelium basal lamina. The antisera affected the growth pattern and the morphology of the individual axons in two ways: in the presence of a-RBL I the short axons were less directed, developed more and longer side branches, and the lamellipodia of the growth cones were reduced in size compared to axons from control cultures. In the presence of a-RBL II and a-GBL, axons grew slowly out from the explants as very thick bundles, strikingly different from axons in control cultures. The antiserum to pigment epithelium basal lamina induced both strong fasciculation and disorganization of the linear fiber extension, being intermediate between the two types of effects observed after antiserum addition. The results suggest that adhesive matrix molecules in basal laminae have important functions in elongation, fasciculation and in the morphology of growing axons.

Epithelial induction of osteogenesis in embryonic chick mandibular mesenchyme: a possible role for basal lamina

1983 ◽  
Vol 61 (8) ◽  
pp. 967-979 ◽  
Author(s):  
R. J. Van Exan ◽  
B. K. Hall
Keyword(s):  
Basal Lamina ◽  
Mesenchymal Cell ◽  
Embryonic Chick ◽  
Cell Contacts ◽  
Ultrastructural Studies ◽  
Extracellular Products ◽  
Series Of Experiments ◽  
Inductive Mechanism

The initiation of osteogenesis at 7 days in the embryonic chick mandibular mesenchyme depends on an epithelial induction in the mandible to day 4. This article reviews a series of experiments conducted to study the nature of this inductive mechanism. Transfilter tissue recombinations were used to determine whether direct tissue apposition was required for induction. Ultrastructural studies of the epithelial–mesenchymal interface were conducted to see if direct epithelial–mesenchymal cell–cell contacts occurred during the inductive stage in vivo. Epithelial cells were cultured on Millipore filters for 28 days and allowed to deposit extracellular products. These products were tested for inductive activity. Findings from these three sets of experiments were discussed with respect to the inductive mechanism. Our results indicate that the induction is not mediated by a diffusible substance and that direct apposition of the two tissues is required. The mechanism of induction, however, does not require direct epithelial–mesenchymal cell to cell contacts. This suggests that a nondiffusible component of the extracellular matrix may be involved. Epithelial extracellular products are inductively active and have the appearance of basal lamina. The active component of the extracellular product is proteinaceous, perhaps collagen, and appears to be situated in the epithelial basal lamina. The role of basal lamina in epithelial–mesenchymal interactions is discussed.

Epithelial induction of osteogenesis in embryonic chick mandibular mesenchyme studied by transfilter tissue recombinations

Development ◽  
1984 ◽  
Vol 79 (1) ◽  
pp. 225-242
Author(s):  
R. J. van Exan ◽  
B. K. Hall
Keyword(s):  
Epithelial Cell ◽  
Basal Lamina ◽  
Chorioallantoic Membrane ◽  
Embryonic Chick ◽  
In Ovo ◽  
Cell Product ◽  
Tissue Separation ◽  
Inductive Mechanism ◽  
Millipore Filters ◽  
Sem Studies

The initiation of osteogenesis in the mandibular mesenchyme of the embryonic chick at 7 days is dependent upon an epithelial induction which occurs in the mandible up to the fourth day in ovo. In the present study, transfilter tissue recombinations were used to study this inductive mechanism. The epithelial and mesenchymal components of the mandibles were separated before the completion of the induction and recombined to form transfilter explants which were either cultured for 9 days or grafted onto the chorioallantoic membrane for host embryos for 7 days. Control experiments demonstrated that the tissue separation and recombination techniques did not interfere with the normal epithelial induction, and confirmed that mandibular mesenchyme isolated at this stage was incapable of forming bone. Bone was observed in 86 % of the CAM-grafted intact mandible controls and in 80 % of the cultured intact mandible controls. Bone failed to form in the mesenchyme of transfilter explants when Millipore filters with 0·45 μm pores were used. Bone was observed as frequently as in control explants when the mandibular mesenchyme was separated from its epithelium by 0·8 μm or 0·4 μm porosity Nuclepore filters. Only about 30% of the transfilter explants prepared with 0·1 μm porosity Nuclepore filters formed bone and none of the explants prepared with 0·03 μm porosity Nuclepore filters formed bone. SEM studies demonstrated a distinct correlation between the formation of bone in transfilter explants and the ability of the epithelium and mesenchyme to penetrate the pores of the filters. Thus, the present study provides evidence that the site of the induction is restricted to the epithelial—mesenchymal interface, and that the induction is not mediated by a diffusible substance. The nature of the inductive mechanism is discussed with respect to this and other recent studies which suggest that the induction may be mediated by a non-diffusible epithelial cell product resident in the epithelial basal lamina.

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

Dexamethasone Effect on Embryonic Chick Respiratory Epithelium

1982 ◽  
Vol 40 ◽  
pp. 248-249
Author(s):  
M.R. Richter ◽  
R.V. Blystone
Keyword(s):  
Lung Development ◽  
Critical Role ◽  
Respiratory Epithelium ◽  
Chick Embryos ◽  
Embryonic Chick ◽  
White Leghorn ◽  
Lung Maturation ◽  
Synthetic Analogs ◽  
Lung Physiology ◽  
Avian Lung

Dexamethasone and other synthetic analogs of corticosteroids have been employed clinically as enhancers of lung development. The mechanism(s) by which this steroid induction of later lung maturation operates is not clear. This study reports the effect on lung epithelia of dexamethasone administered at different intervals during development. White Leghorn chick embryos were used so as to remove possible maternal and placental influences on the exogenously applied steroid. Avian lung architecture does vary from mammals; however, respiratory surfactant produced by the lung epithelia serves an equally critical role in avian lung physiology.

Ultrastructure of the basal lamina of bovine ovarian follicles and its relationship to the membrana granulosa

Reproduction ◽  
2000 ◽  
pp. 221-228 ◽  
Author(s):  
HF Irving-Rodgers ◽  
RJ Rodgers
Keyword(s):  
Basal Lamina ◽  
Granulosa Cells ◽  
Light And Electron Microscopy ◽  
Single Layer ◽  
Antral Follicle ◽  
Basal Cells ◽  
Preantral Follicles ◽  
Antral Follicles ◽  
Cellular Processes ◽  
Innermost Layer

Different morphological phenotypes of follicular basal lamina and of membrana granulosa have been observed. Ten preantral follicles (< 0. 1 mm), and 17 healthy and six atretic antral follicles (0.5-12 mm in diameter) were processed for light and electron microscopy to investigate the relationship the between follicular basal lamina and membrana granulosa. Within each antral follicle, the shape of the basal cells of the membrana granulosa was uniform, and either rounded or columnar. There were equal proportions of follicles </= 4 mm in diameter with columnar basal cells and with rounded basal cells. Larger follicles had only rounded basal cells. Conventional basal laminae of a single layer adjacent to the basal granulosa cells were observed in healthy follicles at the preantral and antral stages. However, at the preantral stage, the conventional types of basal lamina were enlarged or even partially laminated. A second type of basal lamina, described as 'loopy', occurred in about half the preantral follicles and in half the antral follicles </= 4 mm diameter. 'Loopy' basal laminae were not observed in larger follicles. 'Loopy' basal laminae were composed of basal laminae aligning the basal surface of basal granulosa cells, but with additional layers or loops often branching from the innermost layer. Each loop was usually < 1 microm long and had vesicles (20-30 nm) attached to the inner aspect. Basal cellular processes were also common, and vesicles could be seen budding off from these processes. In antral follicles, conventional basal laminae occurred in follicles with rounded basal granulosa cells. Other follicles with columnar cells, and atretic follicles, had the 'loopy' basal lamina phenotype. Thus, follicles have different basal laminae that relate to the morphology of the membrana granulosa.

scholarly journals Primary Cultures of Embryonic Chicken Neurons for Sensitive Cell-Based Assay of Botulinum Neurotoxin: Implications for Therapeutic Discovery

2007 ◽  
Vol 12 (3) ◽  
pp. 370-377 ◽  
Author(s):  
Andrea M. Stahl ◽  
Gordon Ruthel ◽  
Edna Torres-Melendez ◽  
Tara A. Kenny ◽  
Rekha G. Panchal ◽  
...  
Keyword(s):  
Nervous System ◽  
Botulinum Toxin ◽  
Neutralizing Antibodies ◽  
Botulinum Neurotoxin ◽  
Potent Inhibitor ◽  
Primary Cultures ◽  
Embryonic Chick ◽  
Sensitive Cell ◽  
Botulinum Neurotoxin A ◽  
Therapeutic Compounds

Botulinum toxin is an exceedingly potent inhibitor of neurotransmission across the neuromuscular junction, causing flaccid paralysis and death. The potential for misuse of this deadly poison as a bioweapon has added a greater urgency to the search for effective therapeutics. The development of sensitive and efficient cell-based assays for the evaluation of toxin antagonists is crucial to the rapid and successful identification of therapeutic compounds. The authors evaluated the sensitivity of primary cultures from 4 distinct regions of the embryonic chick nervous system to botulinum neurotoxin A (BoNT/A) cleavage of synaptosomal-associated protein of 25 kD (SNAP-25). Although differences in sensitivity were apparent, SNAP-25 cleavage was detectable in neuronal cells from each of the 4 regions within 3 h at BoNT/A concentrations of 1 nM or lower. Co-incubation of chick neurons with BoNT/A and toxin-neutralizing antibodies inhibited SNAP-25 cleavage, demonstrating the utility of these cultures for the assay of BoNT/A antagonists. ( Journal of Biomolecular Screening 2007:370-377)

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