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Comparative analyses of cranial skeletogenesis and odontogenesis in basal Ray-finned fishes
Pospíšilová, Anna ; Černý, Robert (advisor) ; Přikryl, Tomáš (referee) ; Buchtová, Marcela (referee)
Skeletal (cartilaginous, bony, and dental) tissues undoubtedly exemplify the key innovation of vertebrates. Among all recent vertebrates, the most numerous and successful lineage is represented by the Ray-finned fishes that, accordingly, exhibit amazing variety of skeletal architectures and phenotypic adaptations. In order to depict fundamental principles of fish cranial skeletogenesis the developmental formation of skeletal architectures was described, compared and analyzed using members of early branching fish lineages, that exemplify very different strategies of skeletogenesis. While the Senegal bichirs and the Tropical gars are heavily armored forms with massive exoskeleton and hyperossified dental structures covering the whole oropharyngeal region, the European sterlets, on the contrary, possess mostly cartilaginous skeleton and reduce their dental structures during early development. Whole analysis is underpinned by the Northen pike, teleostean species with lightened skeletal architecture with comparable number of cranial elements. The present study represents the first complex comparative analysis of their skeletogenesis and odontogenesis. This allowed to define developmental strategies founding different lineage-specific skeletal architecture of vertebrates. Comparative description of...
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Dental phenotype variation in voles during the present glacial cycle
Putalová, Tereza ; Horáček, Ivan (advisor) ; Kuneš, Petr (referee)
The phenotype dynamics of arvicolid rodents during the terminal stages of the Vistualian glacial and the earliest Holocene was investigated with aid of a detailed morphometric analyses of extensive dental material from three sedimentary series of that age. The particular attention was paid to the record from a section in Býčí skála cave, Moravian karst, which demonstrated details of the Pleistocene/Holocene transition (12.4-8.4 ky BP) with extraordinary resolution. It revealed that dramatic rearrangements in community structure were accompanied by significant rearrangements of the phenotype dynamics in all arvicolid species. Despite some trends specific for particular species, some common features were identified as well. One of them was a rapid turnover in phenotype structure by the end of Younger Dryas, at time of the Preboreal event. (11.7-11 ky BP), the other was associated with the extensive shifts in community structure and habitat diversity at terminal stage of the Preboreal (9.7-9.3 ky). The core arvicolid species of Preboreal communities, Clethrionomys glareolus, Microtus arvalis, M.agrestis and Arvicola terrestris, exhibited repeated fluctuations during that stage (ll-9,3 ky BP) both in abundance and phenotype characteristics, supposedly related to serial invasion events during that time....
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Genus Sicista (Mammalia, Rodentia) in the fossil record of central Europe: phenotypic variation, taxonomic structure, range dynamics.
Lišková, Tereza ; Horáček, Ivan (advisor) ; Vohralík, Vladimír (referee)
Member of the genus Sicista rank among the rarest and the least known European mammals. They exhibit a number of outstanding specificities (hibernation, aestivation etc.) and extreme capability of a rare range dynamics. Their fossil record is fragmentary and associated with numerous controversies. The present thesis summarizes results of a detailed revision of the fossil record of Sicista from Czech Republic, Slovakia and some other countries. It comprises of about 150 items of the Holocene and Vistualian age as well as from the Middle and Early Pleistocene including earliest records from MN17/Q1 boundary and type material of S. praeloriger from Q1 Betfia. Compared to a sample of extant population, variation dynamics of both metrical and nonmetrical dental traits was examined in details with particular attention to phenotype patterns of particular fossil samples. The results demonstrated extensive amount of both within- and between-population variation and rather limited validity of commonly used discrimination criteria of extant clades. Nevertheless, we succeeded in species identification of considerable part of numerous Holocene and Vistulian records which revealed (i) a range expansion of S. subtilis s.l. during MIS 3 with persistent distribution in lowland regions of Central Europe in the Late...
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Comparative analyses of cranial skeletogenesis and odontogenesis in basal Ray-finned fishes
Pospíšilová, Anna ; Černý, Robert (advisor) ; Přikryl, Tomáš (referee) ; Buchtová, Marcela (referee)
Skeletal (cartilaginous, bony, and dental) tissues undoubtedly exemplify the key innovation of vertebrates. Among all recent vertebrates, the most numerous and successful lineage is represented by the Ray-finned fishes that, accordingly, exhibit amazing variety of skeletal architectures and phenotypic adaptations. In order to depict fundamental principles of fish cranial skeletogenesis the developmental formation of skeletal architectures was described, compared and analyzed using members of early branching fish lineages, that exemplify very different strategies of skeletogenesis. While the Senegal bichirs and the Tropical gars are heavily armored forms with massive exoskeleton and hyperossified dental structures covering the whole oropharyngeal region, the European sterlets, on the contrary, possess mostly cartilaginous skeleton and reduce their dental structures during early development. Whole analysis is underpinned by the Northen pike, teleostean species with lightened skeletal architecture with comparable number of cranial elements. The present study represents the first complex comparative analysis of their skeletogenesis and odontogenesis. This allowed to define developmental strategies founding different lineage-specific skeletal architecture of vertebrates. Comparative description of...
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Development of dentition in the x-ray image
STOKLASOVÁ, Martina
The topic of the bachelor thesis is to compare the quality of analogic and digital orthopantomograms. The accuracy and legibility of these x-ray photos is assessed via teeth dental age in different areas of mixed dentition at ten-year old children. Further, the thesis analyses the most commont mistakes made when orthopantomogram is taken. In the theoretic part of the thesis the anatomy is described, the development of teeth and teeth marking. Next, the thesis focuses on dental age assessing at grown ups and its methods. Further, the theoretical part describes in detail x-ray machines and techniques in stomatology. The x-ray photos of children and their preparation is a special part of the thesis. The practical part of the thesis formulates goals and research questions. A file and a metodology, which are used in the research are descibed. The dental age is assessed according to a method proposed by Kominek and Rozkovcova, 1984. This method lies in compartmentalization of a developing dental germ of 7 developing stages corresponging with a specific age period. A permanent and a temporary dentures are assessed in schemes and tables and devided according to the development stage of a child. The research of the thesis lied in assessing and comparing of dental age within a file of 100 children with mixed dentition at the age of ten years. The file comprised 50 randomly chosen analogic photos and 50 digital photos. Further, technical mistakes at the photos and the their reasons were assessed and analyzed. The thesis descibes examples of assessing both of analogic photos and digital photos and the mistakes which inable the dentition development assessing. Its clear that digital photos is more accurate and of a higher quality. Thus, its suprising how many mistakes were found on the chosen photos. From today's point of view, analogic photos are a past. Analogic photos showed frequent flaws in quality, such as insufficiant photos development causing artefacts, over- and underlighting, insufficiant settling on the photos. A disadvantage of this way of development were also huge area demands for development of an analogic photos and the necessity of storing of chemicals and films. Paradoxically, in the results of the thesis more mistakes were found on digital rather than on analogic photos in a random choice, which seems a serious problem to me because modern digital methods cannot be compared to history photos as far as their technical possibilities are concerned. When assesing the accuracy of results of the dental age of children, we can find out how many photos can be assessed and how many not. On 20 randomly chosen digital and 20 analogical photos an analysis of the most common mistakes in orthopantomographs was carried out. For the analysis of the mistakes on the photos a frontal part of the denture was chosen, which is the area of the cutters where the most mistakes were cause by incorrect setting of the children's head in the x-ray machine. On 20 analogical photos, 35% of the children were placed in the machine incorrectly, on 20 digital photos the result was 25% of the children. When comparing analogical and digital photos, no difference was found when assessing the dental age. The discussion shows the importance of making orthopantomograph in a high quality at children in the period of denture change and the most common mistakes are commented on. In conclusion, the problematics of orthopantomograph making was summed up, where the most common flaws when making x-ray photos at children were pointed out. These flaws lead to diagnostic inaccuracies. The importance of correct placing of the child when x-ray making was stressed, which was not adhered to at 55% of the children patients whose photos I assessed. This fact is to be taken very seriously because it is an invasive checkup.
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Modulation of the pharyngeal dentition during the vertebrate evolution
Novotná, Štěpánka ; Soukup, Vladimír (advisor) ; Zahradníček, Oldřich (referee)
Teeth represent a key evolutionary novelty of vertebrates. The dentition of the majority of extant vertebrates is present in the oral cavity associated with jaws and palate and/or in the pharyngeal cavity asscociated with the last pharyngeal arch. The ancestral state of the vertebrate dentition is considered to be presence of teeth through the whole oropharyngeal cavity. This state is however preserved only in few members of extant osteichthyans (for example bichir and latimeria). The other vertebrates gradually lost the pharyngeal dentition. The basal groups of actinopterygians meet the conditions of preservation of the ancestral states and are thus relevant for understanding the initial state in the evolution of vertebrate dentitions. On the other hand, some derived actinopterygian lineages contain members with the most specialized pharyngeal dentitions. This bachelor thesis concentrates on the description of pharyngeal dentitions accross vertebrates and focuses on members of basal actinopterygian lineages (bichir, sturgeon and gar), which from the point of view of dental evolution represent crutial, although neglected animals. Detailed description of pharyngeal dentitions of these animals will form a basis for the upcoming Diploma project. Key words: teeth, dentition, evolution, vertebrates, pharynx
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Dental stem cells during development of vertebrate dentitions
Pešanová, Věra ; Soukup, Vladimír (advisor) ; Hovořáková, Mária (referee)
Vertebrate dentition is a dynamic structure, which continuously renews its elements, the teeth. Continuous tooth renewal is enabled thanks to the presence of epithelial and mesenchymal dental stem cells. Epithelial stem cells are located in the dental lamina, which, together with the adjacent mesenchyme, takes part in regulation of the stem cells through a complicated signalling network. This network is responsible for the positioning, correct amount, inactivity, proliferation and differention of the stem cells. Vertebrate dentitions are morphologically diverse. However, their development is, to a certain extent, controlled by shared evolutionarily conserved mollecular mechanisms. For example, epithelial stem cells of all vertebrate groups examined so far express the transcription factor Sox2 and are shown to be regulated by signalling pathways, such as Wnt/β-catenin, Shh, Fgf and Bmp. Due to the rich diversity in dental lamina morphologies, the locations of presumptive stem cells correspondingly differ among vertebrates. This thesis summarizes current knowledge on dental stem cells in each lineage to identify shared and derived aspects of vertebrate dentitions.
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Age estimation in two recent European population by assessment of permanent tooth mineralization
Černá, Magdaléna ; Velemínská, Jana (advisor) ; Stránská, Petra (referee)
Age estimation is a common requirement in forensic, bioarcheological and biomedical practice. This master thesis deals with age estimation based on permanent tooth mineralization according to Demirjian et al. (1973). The research material consisted of orthopantomograms of 716 Czech and 743 French children aged between 4 and 15 years. The purpose of this study was to analyse the suitability of the original French-Canadian standards for age estimation (Demirjian a Goldstein, 1976) and the recent Belgian standards (Willems et al., 2001) in Czech and French population. Another aim of the study was to evaluate the accuracy of the neural network method that represents a completely new approach in data prediction. In order to express the accuracy of estimate we used mean and median of difference between chronological and dental age, and RMS error. Using logistic regression, differences in tooth mineralization between Czech and French population and between girls and boys were also evaluated. Our results indicate that the French-Canadian standards gave a consistent overestimation of dental age compared with chronological age. Mean difference was 0,33 years for Czech children and 0,45 and 0,46 years for French girls and boys, respectively. We found that Willem's method and neural network method were more...
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Dental phenotype variation in voles during the present glacial cycle
Putalová, Tereza ; Horáček, Ivan (advisor) ; Kuneš, Petr (referee)
The phenotype dynamics of arvicolid rodents during the terminal stages of the Vistualian glacial and the earliest Holocene was investigated with aid of a detailed morphometric analyses of extensive dental material from three sedimentary series of that age. The particular attention was paid to the record from a section in Býčí skála cave, Moravian karst, which demonstrated details of the Pleistocene/Holocene transition (12.4-8.4 ky BP) with extraordinary resolution. It revealed that dramatic rearrangements in community structure were accompanied by significant rearrangements of the phenotype dynamics in all arvicolid species. Despite some trends specific for particular species, some common features were identified as well. One of them was a rapid turnover in phenotype structure by the end of Younger Dryas, at time of the Preboreal event. (11.7-11 ky BP), the other was associated with the extensive shifts in community structure and habitat diversity at terminal stage of the Preboreal (9.7-9.3 ky). The core arvicolid species of Preboreal communities, Clethrionomys glareolus, Microtus arvalis, M.agrestis and Arvicola terrestris, exhibited repeated fluctuations during that stage (ll-9,3 ky BP) both in abundance and phenotype characteristics, supposedly related to serial invasion events during that time....
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Dlx genes in odontogenesis and craniofacial mophogenesis in bichirs
Macháčová, Simona ; Černý, Robert (advisor) ; Zahradníček, Oldřich (referee)
Bichirs, Polypteriformes, are a basal group of vertebrates with many unique characters as ganoid scales, fleshy pectoral fin, spiraculum or paired lung originated from ventral outpocketing from floor of pharynx. Among the most notable is also the dentition, which contatin teeth among whole area of oropharyngeal cavity. This arrangement is not easily call oral and pharyngeal, what is recently used e.g. for medaka, because it is only one dention with teeth on majority of oral as well as pharyngeal elements. This diploma thesis utilizes expression patterns of Dlx genes to visualize morphogenesis of dentition and pharyngeal arches in the Senegal Bichir (Polypterus senegalus). The very first developing teeth of oral dentition, as well as its further patterning were detected and accurately located using gene expression analyses. It was also discovered an interesting histological context connected with unique mouth opening mechanism during early development of teeth in oral cavity. Another discussion point is establishment of dorsoventral polarization in pharyngeal arches development of bichir based on results from Dlx gene expression analysis. Powered by TCPDF (www.tcpdf.org)
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