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The role of rudimentary structures in odontogenesis.
Lochovská, Kateřina ; Hovořáková, Mária (advisor) ; Buchtová, Marcela (referee) ; Štembírek, Jan (referee)
In vivo organogenesis is based on the temporal-spatial developmental processes that depend on cell behaviour, for example on their growth, migration, differentiation and intercellular interactions. Such behaviour is regulated by appropriate transient expression of various signalling molecules. Despite the significant advances in therapeutic strategies, the secret of the development of the biological replacement of a damaged or missing tooth has not yet been revealed. In this context, animal models provide a powerful tool for studying tooth normogenesis and pathogenesis in both basic and applied research. Early development of the tooth shares similar morphological and molecular features with other ectodermal organs. At the same time, these features are largely preserved also between species, which is advantageous for the use of model organisms. The dental formula of both: the human and the mouse are reduced against a common ancestor, but both groups of organisms evince simple as well as multicusped teeth. In both, structures called rudimentary were found. These structures are suppressed during ontogenetic development and generally they are not attributed to essential functions. That is why we aimed to study dental rudiments in detail and reveal their function in odontogenesis. This work presents new...
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The role of rudimentary structures in odontogenesis.
Lochovská, Kateřina ; Hovořáková, Mária (advisor) ; Buchtová, Marcela (referee) ; Štembírek, Jan (referee)
In vivo organogenesis is based on the temporal-spatial developmental processes that depend on cell behaviour, for example on their growth, migration, differentiation and intercellular interactions. Such behaviour is regulated by appropriate transient expression of various signalling molecules. Despite the significant advances in therapeutic strategies, the secret of the development of the biological replacement of a damaged or missing tooth has not yet been revealed. In this context, animal models provide a powerful tool for studying tooth normogenesis and pathogenesis in both basic and applied research. Early development of the tooth shares similar morphological and molecular features with other ectodermal organs. At the same time, these features are largely preserved also between species, which is advantageous for the use of model organisms. The dental formula of both: the human and the mouse are reduced against a common ancestor, but both groups of organisms evince simple as well as multicusped teeth. In both, structures called rudimentary were found. These structures are suppressed during ontogenetic development and generally they are not attributed to essential functions. That is why we aimed to study dental rudiments in detail and reveal their function in odontogenesis. This work presents new...
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Tracing the fate of cell populations from regressive tooth primordia during ontogenesis
Řadová, Marie ; Hovořáková, Mária (advisor) ; Černý, Jan (referee)
(v anglickém jazyce) Development of tooth primordia in mice is an important model for study of odontogenesis. Several dental rudiments develop during the mouse embryogenesis. These structures develop in functional teeth in their phylogenetically older relatives. Similarly, we can initiate growth of teeth from these germs in some mutant mice. In my diploma thesis we have focused on the importance of rudimentary structures with odontogenic potential in postnatal individuals. As a model of development, we have chosen a cell population originating from rudimentary primordia MS (mesial segment) that develops in diastema of the lower jaw during the embryonic day 12.5. Using the inducible Cre-lox technology we have marked the cells which are part of the signal domain of primordia at this time. As a marker of these cells we have used gene Shh. We have found out that these cells persist prenataly and also postnatally. Further we have isolated this cell area and we have tested it using a variety of methods. We have shown that in the cells of postnatal individual are expressed markers of stem cells (Sox2, Bmi1, Gli1) and also genes for major enamel matrix structural proteins: ameloblastin and amelogenin. The same stem cell markers are also expressed in vitro culture of the isolated cells. This cell population...
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Formation of human dental anomalies in odontogenesis of mouse models with gene defects.
Lochovská, Kateřina ; Hovořáková, Mária (advisor) ; Peterka, Miroslav (referee)
Laboratory mouse is a appropriate experimental model for studies on normal tooth development mechanisms and for understanding of etio-pathogenesis of dental anomalies in humans. Mouse dentition consists of one incisor separated from three molars by toothless diastema in each jaw quadrant. Although an adult mice diastema does not contain teeth, rudimentary tooth primordia (MS, R2) appear here during embryonic development. However, their development stops and consequently functional tooth does not arise here. It is known that in mice with mutations in Spry2 and Spry4 genes, supernumerary teeth arise in antemolar region. The understanding of the temporo-spatial dynamics of signaling centers in Spry2/Spry4 double transgenic mice may help to elucidate the role of these embryonic diastemal buds in supernumerary tooth formation. The research of possible regeneration of dental anomalies in off-spring of crossing Spry4 deficient mice with supernumerary teeth formation with Eda deficient mice with predisposition to reduced dentition could be the way to elucidating of mechanism of dental pathologies development in general. Our aim was to describe temporal and spatial dynamics of Shh signaling domains in Spry2/Spry4 embryos, because Shh is one of the markers of early odontogenesis and determining of...
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