scholarly journals Oral and Palatal Dentition of Axolotl Arises From a Common Tooth-Competent Zone Along the Ecto-Endodermal Boundary

2021 ◽  
Vol 8 ◽  
Author(s):  
Vladimír Soukup ◽  
Akira Tazaki ◽  
Yosuke Yamazaki ◽  
Anna Pospisilova ◽  
Hans-Henning Epperlein ◽  
...  
Keyword(s):  
Expression Patterns ◽  
Germ Layers ◽  
Contact Zones ◽  
Simultaneous Addition ◽  
Potential Source ◽  
Single Tooth ◽  
Oropharyngeal Cavity ◽  
Oral Ectoderm ◽  
Tooth Germs ◽  
Study Development

Vertebrate dentitions arise at various places within the oropharyngeal cavity including the jaws, the palate, or the pharynx. These dentitions develop in a highly organized way, where new tooth germs are progressively added adjacent to the initiator center, the first tooth. At the same time, the places where dentitions develop house the contact zones between the outer ectoderm and the inner endoderm, and this colocalization has instigated various suggestions on the roles of germ layers for tooth initiation and development. Here, we study development of the axolotl dentition, which is a complex of five pairs of tooth fields arranged into the typically tetrapod outer and inner dental arcades. By tracking the expression patterns of odontogenic genes, we reason that teeth of both dental arcades originate from common tooth-competent zones, one present on the mouth roof and one on the mouth floor. Progressive compartmentalization of these zones and a simultaneous addition of new tooth germs distinct for each prospective tooth field subsequently control the final shape and composition of the axolotl dentition. Interestingly, by following the fate of the GFP-labeled oral ectoderm, we further show that, in three out of five tooth field pairs, the first tooth develops right at the ecto-endodermal boundary. Our results thus indicate that a single tooth-competent zone gives rise to both dental arcades of a complex tetrapod dentition. Further, we propose that the ecto-endodermal boundary running through this zone should be accounted for as a potential source of instruction factors instigating the onset of the odontogenic program.

scholarly journals Expression, localization and synthesis of small leucine-rich proteoglycans in developing mouse molar tooth germ

2020 ◽  
Vol 64 (1) ◽  
Author(s):  
Angammana Randilini ◽  
Kaoru Fujikawa ◽  
Shunichi Shibata
Keyword(s):  
Organ Culture ◽  
Developmental Stages ◽  
Tooth Development ◽  
Expression Patterns ◽  
Tooth Germ ◽  
Molar Tooth ◽  
Cervical Region ◽  
Metabolic Labeling ◽  
Tooth Formation ◽  
Tooth Germs

The gene expression and protein synthesis of small leucine-rich proteoglycans (SLRPs), including decorin, biglycan, fibromodulin, and lumican, was analyzed in the context of the hypothesis that they are closely related to tooth formation. In situ hybridization, immunohistochemistry, and organ culture with metabolic labeling of [35S] were carried out in mouse first molar tooth germs of different developmental stages using ICR mice at embryonic day (E) 13.5 to postnatal day (P) 7.0. At the bud and cap stage, decorin mRNA was expressed only in the surrounding mesenchyme, but not within the tooth germ. Biglycan mRNA was then expressed in the condensing mesenchyme and the dental papilla of the tooth germ. At the apposition stage (late bell stage), both decorin and biglycan mRNA were expressed in odontoblasts, resulting in a switch of the pattern of expression within the different stages of odontoblast differentiation. Decorin mRNA was expressed earlier in newly differentiating odontoblasts than biglycan. With odontoblast maturation and dentin formation, decorin mRNA expression was diminished and localized to the newly differentiating odontoblasts at the cervical region. Simultaneously, biglycan mRNA took over and extended its expression throughout the new and mature odontoblasts. Both mRNAs were expressed in the dental pulp underlying the respective odontoblasts. At P7.0, both mRNAs were weakly expressed but maintained their spatial expression patterns. Immunostaining showed that biglycan was localized in the dental papillae and pulp. In addition, all four SLRPs showed clear immunostaining in predentin, although the expressions of fibromodulin and lumican mRNAs were not identified in the tooth germs examined. The organ culture data obtained supported the histological findings that biglycan is more predominant than decorin at the apposition stage. These results were used to identify biglycan as the principal molecule among the SLRPs investigated. Our findings indicate that decorin and biglycan show spatial and temporal differential expressions and play their own tissue-specific roles in tooth development.

Expression patterns of genes critical for BMP signaling pathway in developing human primary tooth germs

2014 ◽  
Vol 142 (6) ◽  
pp. 657-665 ◽  
Author(s):  
Xiuqing Dong ◽  
Bin Shen ◽  
Ningsheng Ruan ◽  
Zhen Guan ◽  
Yanding Zhang ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Expression Patterns ◽  
Bmp Signaling ◽  
Primary Tooth ◽  
Tooth Germs

Analysis of expression patterns of IGF-1, caspase-3 and HSP-70 in developing human tooth germs

2015 ◽  
Vol 60 (10) ◽  
pp. 1533-1544 ◽  
Author(s):  
Darko Kero ◽  
Danijela Kalibovic Govorko ◽  
Ivana Medvedec Mikic ◽  
Katarina Vukojevic ◽  
Livia Cigic ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Expression Patterns ◽  
Human Tooth ◽  
Hsp 70 ◽  
Tooth Germs

The ontogeny of tooth succession in Lacerta vivipara Jacquin (1787)

1971 ◽  
Vol 179 (1056) ◽  
pp. 261-289 ◽  
Keyword(s):  
Tooth Development ◽  
Biological Significance ◽  
Tooth Replacement ◽  
Similar Sequence ◽  
Dental Lamina ◽  
Oral Ectoderm ◽  
Three Stages ◽  
Lacerta Vivipara ◽  
Tooth Germs ◽  
Almost All

Edmund (1960) has shown that in the dentitions of almost all non-mammalian vertebrates, teeth are replaced in waves which regularly sweep through alternate tooth positions. He explained the ontogeny of these patterns of tooth replacement in terms of biological units called Zahnreihen whose existence has been accepted by nearly all workers studying tooth replacement. In the present paper it is argued that there is no unequivocal evidence, either during development or in adult animals, that Zahnreihen have any biological significance. Reconstructions were made from serial sections of the developing dentitions in the lower jaws of 15 embryos of Lacerta vivipara . It was evident that Zahnreihen have no significance in this animal. Rudimentary teeth were produced with varying frequency in positions 3, 5, 6, 8, 10 and 13. Contrary to the predictions of all previous theories explaining the ontogeny of tooth development in reptiles it was in these apparently random positions that the first teeth were produced. Furthermore, apart from during the first few days of embryonic dental development, it was clear that the development of a row of alternating teeth was initiated in sequence from the back to the front of the jaw to be followed by a similar sequence of development of the intervening teeth. On the basis of this evidence a new model to explain the sequence of tooth initiation in reptiles is proposed. The following assumptions have been made. (A) Ectomesenchymal cells migrate anteriorly through the developing jaws initiating a reaction from the oral ectoderm. (B) The oral ectoderm develops competence to react to the ectomesenchyme in three stages. First it generates abortive clumps of ectodermal cells; second it becomes capable of inducing the adjacent ectomesenchymal cells to form dentine and third it becomes capable of laying down enamel. (C) At all times the dental lamina has the potential of taking part in tooth development according to the regional competence achieved. (D) Developing tooth germs produce a condition which inhibits tooth development around them. Using these assumptions it is possible to explain all stages in the development of the wave replacement of alternate teeth in L . vivipara . It is also possible to explain previous observations on the ontogeny of reptilian dentitions. The sphere of inhibition which surrounds developing teeth is particularly important because it ensures that developing teeth are evenly spaced through the jaw. It is argued that the wave replacement of alternate teeth is an automatic sequel to this and is of only secondary functional significance.

Expression of Bone Morphogenetic Proteins and Msx Genes during Root Formation

2003 ◽  
Vol 82 (3) ◽  
pp. 172-176 ◽  
Author(s):  
T. Yamashiro ◽  
M. Tummers ◽  
I. Thesleff
Keyword(s):  
Signaling Pathway ◽  
Bone Morphogenetic Proteins ◽  
Root Development ◽  
Root Formation ◽  
Expression Patterns ◽  
Bmp Signaling ◽  
Root Sheath ◽  
Crown Shape ◽  
Msx Genes ◽  
Tooth Germs

Like crown development, root formation is also regulated by interactions between epithelial and mesenchymml tissues. Bone morphogenetic proteins (BMPs), together with the transcription factors Msx1 and Msx2, play important roles in these interactions during early tooth morphogenesis. To investigate the involvement of this signaling pathway in root development, we analyzed the expression patterns of Bmp2, Bmp3, Bmp4, and Bmp7 as well as Msx1 and Msx2 in the roots of mouse molars. Bmp4 was expressed in the apical mesenchyme and Msx2 in the root sheath. However, Bmps were not detected in the root sheath epithelium, and Msx transcripts were absent from the underlying mesenchyme. These findings indicate that this Bmp signaling pathway, required for tooth initiation, does not regulate root development, but we suggest that root shape may be regulated by a mechanism similar to that regulating crown shape in cap-stage tooth germs. Msx2 expression continued in the epithelial cell rests of Malassez, and the nearby cementoblasts intensely expressed Bmp3, which may regulate some functions of the fragmented epithelium.

The homeobox gene Hox 7.1 has specific regional and temporal expression patterns during early murine craniofacial embryogenesis, especially tooth development in vivo and in vitro

Development ◽  
1991 ◽  
Vol 111 (2) ◽  
pp. 269-285 ◽  
Author(s):  
A. Mackenzie ◽  
G.L. Leeming ◽  
A.K. Jowett ◽  
M.W. Ferguson ◽  
P.T. Sharpe
Keyword(s):  
Neural Crest ◽  
Tooth Development ◽  
Expression Patterns ◽  
Homeobox Gene ◽  
Branchial Arch ◽  
Developing Brain ◽  
Stage Of Development ◽  
Tooth Germs

Hox 7.1 is a murine homeobox-containing gene expressed in a range of neural-crest-derived tissues and areas of putative epithelial-mesenchymal interactions during embryogenesis. We have examined the expression of Hox 7.1 during craniofacial development in the mouse embryo between days 8 and 16 of development. Whereas facial expression at day 10 of gestation is broadly localised in the neural-crest-derived mesenchyme of the medial nasal, lateral nasal, maxillary and mandibular processes, by day 12 expression is restricted to the mesenchyme immediately surrounding the developing tooth germs in the maxillary and mandibular processes. Hox 7.1 expression in the mesenchyme of the dental papilla and follicle is maximal at the cap stage of development and progressively declines in the bell stage prior to differentiation of odontoblasts and ameloblasts. Hox 7.1 expression in tooth germs is independent of overall embryonic stage of development but is dependent on stage of development of the individual tooth. Similar patterns of transient Hox 7.1 expression can also be detected in tooth germs in vitro in organ cultures of day 11 first branchial arch explants cultured for up to 7 days. Hox 7.1 is also expressed early in development (days 10/11) in the epithelium of the developing anterior pituitary (Rathke's pouch), the connective tissue capsule and meninges of the developing brain, and specific regions of neuroepithelium in the developing brain.

scholarly journals Molecular patterning during the development of Phoronopsis harmeri reveals similarities to rhynchonelliform brachiopods

EvoDevo ◽  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Carmen Andrikou ◽  
Yale J. Passamaneck ◽  
Chris J. Lowe ◽  
Mark Q. Martindale ◽  
Andreas Hejnol
Keyword(s):  
Cell Fate ◽  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Expression Patterns ◽  
Embryonic Patterning ◽  
Dynamic Expression ◽  
Oral Ectoderm ◽  
Axis Specification ◽  
Phoronopsis Harmeri ◽  
Mode Of Development

Abstract Background Phoronids, rhynchonelliform and linguliform brachiopods show striking similarities in their embryonic fate maps, in particular in their axis specification and regionalization. However, although brachiopod development has been studied in detail and demonstrated embryonic patterning as a causal factor of the gastrulation mode (protostomy vs deuterostomy), molecular descriptions are still missing in phoronids. To understand whether phoronids display underlying embryonic molecular mechanisms similar to those of brachiopods, here we report the expression patterns of anterior (otx, gsc, six3/6, nk2.1), posterior (cdx, bra) and endomesodermal (foxA, gata4/5/6, twist) markers during the development of the protostomic phoronid Phoronopsis harmeri. Results The transcription factors foxA, gata4/5/6 and cdx show conserved expression in patterning the development and regionalization of the phoronid embryonic gut, with foxA expressed in the presumptive foregut, gata4/5/6 demarcating the midgut and cdx confined to the hindgut. Furthermore, six3/6, usually a well-conserved anterior marker, shows a remarkably dynamic expression, demarcating not only the apical organ and the oral ectoderm, but also clusters of cells of the developing midgut and the anterior mesoderm, similar to what has been reported for brachiopods, bryozoans and some deuterostome Bilateria. Surprisingly, brachyury, a transcription factor often associated with gastrulation movements and mouth and hindgut development, seems not to be involved with these patterning events in phoronids. Conclusions Our description and comparison of gene expression patterns with other studied Bilateria reveals that the timing of axis determination and cell fate distribution of the phoronid shows highest similarity to that of rhynchonelliform brachiopods, which is likely related to their shared protostomic mode of development. Despite these similarities, the phoronid Ph. harmeri also shows particularities in its development, which hint to divergences in the arrangement of gene regulatory networks responsible for germ layer formation and axis specification.

scholarly journals Molecular patterning during the development of Phoronopsis harmeri reveals similarities to rhynchonelliform brachiopods

2019 ◽  
Author(s):  
Carmen Andrikou ◽  
Yale J. Passamaneck ◽  
Chris J. Lowe ◽  
Mark Q. Martindale ◽  
Andreas Hejnol
Keyword(s):  
Cell Fate ◽  
Regulatory Networks ◽  
Expression Patterns ◽  
Dynamic Expression ◽  
Evolutionarily Conserved ◽  
Oral Ectoderm ◽  
Gene Regulatory ◽  
Phoronopsis Harmeri ◽  
Evolutionary Lineages ◽  
Germ Layer Formation

AbstractBackgroundAnswering the question how conserved patterning systems are across evolutionary lineages requires a broad taxon sampling. Phoronid development has previously been studied using fate mapping and morphogenesis, yet molecular descriptions are missing. Here we report the expression patterns of the evolutionarily conserved anterior (otx, gsc, six3/6, nk2.1), posterior (cdx, bra) and endomesodermal (foxA, gata4/5/6, twist) markers in the phoronid Phoronopsis harmeri.ResultsThe transcription factors foxA, gata4/5/6 and cdx show conserved expression in patterning the development and regionalization of the phoronid embryonic gut, with foxA expressed in the presumptive foregut, gata4/5/6 demarcating the midgut and cdx confined to the hindgut. Surprisingly, brachyury, an evolutionary conserved transcription factor often associated with gastrulation movements and patterning of the mouth and hindgut, seems to be unrelated with gastrulation and mouth patterning in phoronids. Furthermore, six3/6, a well-conserved anterior marker, shows a remarkably dynamic expression, demarcating not only the apical organ and the oral ectoderm, but also clusters of cells of the developing midgut and the anterior mesoderm, similar to what has been reported for brachiopods, bryozoans and some deuterostome Bilateria.ConclusionsOur comparison of gene expression patterns with other studied Bilateria reveals that the timing of axis determination and cell fate distribution of the phoronid shows highest similarities to rhynchonelliform brachiopods. Despite these similarities, the phoronid P. harmeri shows also particularities in its development, which hint to divergences in the arrangement of gene regulatory networks responsible for germ layer formation and axis specification.

How SIMS microscopy can be used in medicine

1992 ◽  
Vol 50 (2) ◽  
pp. 1602-1603
Author(s):  
Philippe Fragu
Keyword(s):  
Mass Spectrometry ◽  
Biomedical Applications ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Elements ◽  
Biological Applications ◽  
The Past ◽  
Potential Source ◽  
Secondary Ion ◽  
Chemical Integrity ◽  
Scientific Endeavour

The identification, localization and quantification of intracellular chemical elements is an area of scientific endeavour which has not ceased to develop over the past 30 years. Secondary Ion Mass Spectrometry (SIMS) microscopy is widely used for elemental localization problems in geochemistry, metallurgy and electronics. Although the first commercial instruments were available in 1968, biological applications have been gradual as investigators have systematically examined the potential source of artefacts inherent in the method and sought to develop strategies for the analysis of soft biological material with a lateral resolution equivalent to that of the light microscope. In 1992, the prospects offered by this technique are even more encouraging as prototypes of new ion probes appear capable of achieving the ultimate goal, namely the quantitative analysis of micron and submicron regions. The purpose of this review is to underline the requirements for biomedical applications of SIMS microscopy.Sample preparation methodology should preserve both the structural and the chemical integrity of the tissue.

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