The influence of the dental papilla on the development of tooth shape in embryonic mouse tooth germs

Development ◽  
1969 ◽  
Vol 21 (1) ◽  
pp. 131-148
Author(s):  
Edward J. Kollar ◽  
Grace R. Baird
Keyword(s):  
Tissue Differentiation ◽  
Embryonic Mouse ◽  
Tooth Shape ◽  
Structural Specificity ◽  
Dental Papilla ◽  
Epithelial Structure ◽  
Tooth Germs ◽  
Labile State

Studies of epithelio-mesenchymal interactions during embryonic organogenesis have led to a number of conclusions regarding the nature of cellular and tissue differentiation (McLoughlin, 1963; Grobstein, 1967). For example, the importance of both the epithelium and the mesenchyme and the dependence of some systems on a limited number of specific mesenchymal tissues have been pointed out (Hilfer, 1968). Intimately connected with the analysis of the factors that elicit differentiation during such interactions is the question of structural specificity of the differentiated structure. Is the directive for the final form of the structure resident in the epithelium, in the mesoderm, or in both? Can a seemingly stable epithelium undergo transformation to a more labile state and respond to a new interaction with the result that a new epithelial structure is formed (Billingham & Silvers, 1963, 1968)?

Tissue interactions in embryonic mouse tooth germs

Development ◽  
1970 ◽  
Vol 24 (1) ◽  
pp. 159-171
Author(s):  
Edward J. Kollar ◽  
Grace R. Baird
Keyword(s):  
Enamel Organ ◽  
Oral Epithelium ◽  
Embryonic Mouse ◽  
Tooth Shape ◽  
Structural Specificity ◽  
Dental Papilla ◽  
Tissue Interactions ◽  
Dental Epithelium ◽  
Tooth Germs

The ability of fragments of incisor enamel organ and lip-furrow epithelium from 15- and 16-day old embryonic mice to regulate into harmonious tooth constructions is described. The cervical loop and upper half portions of the incisor enamel organ were confronted with incisor or molar dental papillae. Similar combinations were made from lip-furrow epithelium and incisor or molar papillae. The cultures were grown in the anterior chambers of homologous host eyes. The epithelial fragments from the incisor enamel organ when associated with the dental papillae reconstruct teeth typical in all respects; enamel and dentin matrices are deposited. Lip-furrow epithelium arises from the oral epithelium and is temporally and spatially related to the incisor dental epithelium proper. This ectopic epithelium was confronted by incisor and molar papillae. Harmonious teeth developed in these explants. It is concluded that the ability of the dental papillae to elicit new cytodifferentiative and biochemical syntheses from the lip-furrow epithelium indicates that the dental papillae act inductively during tooth ontogeny. The shape of the teeth reconstructed from enamel organ fragments and lip-furrow epithelium were incisiform or molariform in response to the incisor or molar dental papillae. These data confirm the conclusion that the structural specificity for tooth shape resides in the dental papilla.

Opg, Rank, and Rankl in Tooth Development: Co-ordination of Odontogenesis and Osteogenesis

2004 ◽  
Vol 83 (3) ◽  
pp. 241-244 ◽  
Author(s):  
A. Ohazama ◽  
J.-M. Courtney ◽  
P.T. Sharpe
Keyword(s):  
Tooth Development ◽  
Nuclear Factor Κb ◽  
Cellular Interactions ◽  
Rankl Expression ◽  
Dental Papilla ◽  
Spatiotemporal Expression ◽  
Receptor Activator ◽  
Explant Cultures ◽  
Enamel Epithelium ◽  
Tooth Germs

Osteoprotegerin (OPG), receptor activator of nuclear factor-κB (RANK), and RANK ligand (RANKL) are mediators of various cellular interactions, including bone metabolism. We analyzed expression of these three genes during murine odontogenesis from epithelial thickening to cytodifferentiation stages. Opg showed expression in the thickening and bud epithelium. Expression of Opg and Rank was observed in both the internal and the external enamel epithelium as well as in the dental papilla mesenchyme. Although Rankl expression was not detected in tooth epithelium or mesenchyme, it was expressed in pre-osteogenic mesenchymal cells close to developing tooth germs. All three genes were detected in developing dentary bone at P0. The addition of exogenous OPG to explant cultures of tooth primordia produced a delay in tooth development that resulted in reduced mineralization. We propose that the spatiotemporal expression of these molecules in early tooth and bone primordia cells has a role in co-ordinating bone and tooth development.

Tissue interactions in embryonic mouse tooth germs

Development ◽  
1970 ◽  
Vol 24 (1) ◽  
pp. 173-186
Author(s):  
Edward J. Kollar ◽  
Grace R. Baird
Keyword(s):  
Hair Follicles ◽  
The Other ◽  
Embryonic Mouse ◽  
Plantar Surface ◽  
Tissue Interactions ◽  
Other Hand ◽  
Dental Epithelium ◽  
Tooth Germs

The response of embryonic mouse dental epithelium and mesoderm to tissues of ectopic origin was examined. Isolated molar or incisor mesoderm was confronted with epithelium isolated from the plantar surface of the embryonic mouse foot plate or from the snout. Harmoniously structured teeth were formed from the foot epithelium and incisor or molar mesoderm. These data are interpreted as an unequivocal demonstration of the inductive role of the dental mesenchyme. Teeth were absent in confrontations of dental mesenchyme and snout epithelium. The presence of hair follicles in these explants is described and discussed with reference to other integumental epithelio-mesenchymal interactions. Dental epithelium forms keratinizing surface-like epithelium and invading bands of epithelium in association with foot mesoderm; definitive structures are not formed. On the other hand, when incisor or molar epithelium is associated with snout mesoderm, hair follicles are seen in addition to keratinizing surface-like epithelial configurations. The roles of the epithelial and mesenchymal tissues and the nature of epithelio-mesenchymal interactions in the developing mouse integument are discussed.

scholarly journals Collagen analysis in human tooth germ papillae

2006 ◽  
Vol 17 (3) ◽  
pp. 208-212 ◽  
Author(s):  
Ivete Jorge Abrahão ◽  
Manoela Domingues Martins ◽  
Emílio Katayama ◽  
João Humberto Antoniazzi ◽  
Angelo Segmentilli ◽  
...  
Keyword(s):  
Growth Regulation ◽  
Type I Collagen ◽  
Staining Technique ◽  
Human Tooth ◽  
Type Iii Collagen ◽  
Type I ◽  
Regular Component ◽  
Type Iii ◽  
Dental Papilla ◽  
Tooth Germs

The extracellular matrix (ECM) performs a very important role in growth regulation and tissue differentiation and organization. In view of this, the purpose of this study was to analyze the collagen, the major organic component of dental pulp ECM, in papillae of human tooth germs in different developmental phases. The maxillas and mandibles of 9 human fetuses ranging from 10 to 22 weeks of intrauterine life were removed and 16 tooth germs (1 in the cap stage, 8 in the early bell stage and 7 in the late bell stage) were obtained. The pieces were processed for histological analysis and stained with hematoxylin-eosin, Masson's Trichrome and picrosirius staining technique. Both types of collagen in the dental papilla were only detected by the picrosirius staining technique under polarized light microscopy. Type III collagen was detected in all specimens. Type I collagen was present in focal areas of the dental papilla only in some specimens. In conclusion, the findings of this study showed that type III collagen is a regular component of the papillae of human tooth germs whereas type I collagen is present in a significantly lesser amount.

Cell—matrix interactions: influence of noncollagenous proteins from dentin on cultured dental cells

Development ◽  
1986 ◽  
Vol 96 (1) ◽  
pp. 195-209
Author(s):  
Herve Lesot ◽  
Anthony J. Smith ◽  
Jean-Marie Meyer ◽  
Aline Staubli ◽  
Jean Victor Ruch
Keyword(s):  
Protein Fractions ◽  
Noncollagenous Proteins ◽  
Embryonic Mouse ◽  
Cytoskeleton Organization ◽  
Preferential Localization ◽  
Basal Pole ◽  
Cell Organization ◽  
Tooth Germs ◽  
Cell Matrix Interactions ◽  
Millipore Filters

Matrix-mediated epitheliomesenchymal interactions control dental cytodifferentiations. Experiments were performed in order to study the effects of noncollagenous proteins extracted from dentin on cultured enamel organs and dental papillae. Seven noncollagenous protein fractions were prepared from rabbit incisor dentin and used as substrates to coat Millipore filters. Embryonic mouse tooth germs were dissociated and the isolated tissues were cultured for 4 days on these different substrates as well as on noncoated Millipore filters. When compared to control cultures, only two protein fractions affected the behaviour of epithelial cells. A slight elongation of the cell body and a preferential localization of the nuclei at the basal pole of the cells in contact with the filter was observed with protein fractions 5 and 6. When dental papillae were cultured on Millipore filters coated either with protein fraction 2 or fraction 6, the mesenchymal cells in contact with the filter elongated, polarized and demonstrated a high metabolic activity. Such modifications in the cell organization, implying changes in the cytoskeleton organization and, or, activity, never occurred spontaneously or in the presence of isolated collagens (I–V), laminin or fibronectin.

Inositol Hexasulphate, a Casein Kinase Inhibitor, Alters Enamel Formation in Cultured Embryonic Mouse Tooth Germs

2000 ◽  
Vol 79 (10) ◽  
pp. 1794-1801 ◽  
Author(s):  
M.A. Torres-Quintana ◽  
S. Lecolle ◽  
D. Septier ◽  
B. Palmier ◽  
S. Rani ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Casein Kinase ◽  
Enamel Formation ◽  
Embryonic Mouse ◽  
Tooth Germs

Preplate neurons in embryonic mouse cortex: Ultrastructural observations using photoconversion of the fluorescent lipophilic dye dil

1992 ◽  
Vol 50 (1) ◽  
pp. 906-907
Author(s):  
Linda C. Hassinger ◽  
James E. Crandall
Keyword(s):  
Mouse Embryos ◽  
Embryonic Mouse ◽  
Cortical Afferents ◽  
Mouse Cortex ◽  
Carbocyanine Dye ◽  
Increased Sensitivity

We have begun to look directly at small numbers of afferent axons to early generated neurons that form the preplate in the developing mouse cortex. The carbocyanine dye Dil (1’1, dioctadecyl-3,3,3’3’-tetramethyl-indocarbocyanine) has proved especially useful for this goal. DiI labels axons and their terminals with greater sensitivity and without some of the disadvantages of axon filling with HRP. The increased sensitivity provided by labeling embryonic axons with DiI has given us new insights into the development of cortical afferents. For instance, we reported originally that afferents from the thalamus were present below the cortex as early as embryonic day 15 (E15) based on HRP injections into mouse embryos. By using DiI placements into the thalamus in aldehyde-fixed brains, we now know that thalamic fibers reach the cortex 24 hrs earlier.

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