|
|
Development of neural crest cells in zebrafish Danio rerio
Psutková, Viktorie ; Machoň, Ondřej (advisor) ; Fabian, Peter (referee) ; Svoboda, Ondřej (referee)
The neural crest is a population of migrating cells found only in vertebrates. Neural crest cells migrate to the head, heart and trunk regions of the body where they transform into different cell types. The cranial neural crest cells differentiate into chondrocytes and tenocytes, among others. The chondrogenic property of the cranial neural crest has given the vertebrates an advantage during evolution. In this paper, we focus on specific functions of the cranial neural crest and its derivatives in zebrafish (Danio rerio). The migration streams of the cranial neural crest follow the antero-posterior axis which is set up by hox genes. The development of the neural crest is controlled by a vast gene regulatory network. Here, we focus on the meis genes within the craniofacial development of zebrafish. For analysis, we used knock out (KO) mutant lines for each paralog of the meis gene (meis1a, meis1b, meis2a, meis2b). Only the meis1b KO and double meis1a1b KO mutants exhibit malformatins of the cranial cartilages, derivatives of the neural crest. We identified changes during cartilage formation. However, the migration of the neural crest into the pharyngeal arches and subsequent chondrocyte condensation remained unchanged. The formation of the facial part of the skull, so-called viscerocranium, is the...
|
|
|
Comparative development & evolution of adenohypophysis in basal fishes
Brezarová, Dominika ; Černý, Robert (advisor) ; Buchtová, Marcela (referee)
The pituitary is a master endocrine gland in the vertebrate head with many crucial roles in producing hormones and controlling secretion of other glands, and with long-standing controversies on its evolution and embryonic origin. Adenohypophysis (ADH), the front lobe of the pituitary, develops from the rostral placode that extensively migrates under the brain to connect the neurohypophysis, evagination of the ventral hypothalamus. Owing to its ectodermal placodal origin, ADH is commonly understood as a part of the vertebrate specific acquisition of our new head. Recently, however, an endodermal contribution to ADH was revealed in the teleost fish, supporting classic claims of a pre-vertebrate origin of this organ from an ancient chordate pharyngeal structure. In this work, early development of ADH was characterized in three species of basal fishes, bichirs, sturgeons, and gars, representing a possible stem-like pattern of early vertebrate craniogenesis. Interestingly, in all three species, both the early development and later migration of ADH is intimately linked with the pharyngeal domain in the rostral head. In sturgeon embryos, ADH migrates in between the brain and the pharyngeal domain, which further separates ADH from the forming mouth. In bichir embryos, ADH was additionally shown to get...
|
|
|
Variability and developmental changes of human face between 3 and 15 years: longitudinal and transversal approach
Moštková, Miroslava ; Velemínská, Jana (advisor) ; Zemková, Daniela (referee)
- 1 - Abstract The intent of this thesis is to evaluate the differences in facial morphology of children between 3 and 15 years of age based on 3D facial models and cross-sectional data. Due to improper use of cross-sectional data for studying growth, the next part of the thesis is focused on the comparison of cross-sectional and longitudinal approaches in research. The longitudinal observation of facial developmental changes can be considered as actual growth. The cross-sectional database contains 839 3D facial models (397 boys, 442 girls). Three previously published longitudinal databases were used for comparison. Their age intervals were as follows: 3 to 6 years (12 boys, 14 girls), 6 to 12 years (15 boys, 18 girls), 12 to 15 years (23 boys, 22 girls). Geometric morphometric methods were used to analyse facial models (Coherent Point Drift - Dense Correspondance Analysis, Per Vertex T-Test and Principal Component Analysis). The results were visualized using superimposition colour maps, shell distance significance maps and their interlacing. When annual consecutive age intervals were used for cross-sectional data, we could not observe the fluency of differences in facial morphology between age categories, which we can observe during actual growth. When wider age intervals were used for cross-sectional...
|
|
|
Variability and developmental changes of human face between 3 and 15 years: longitudinal and transversal approach
Moštková, Miroslava ; Velemínská, Jana (advisor) ; Zemková, Daniela (referee)
- 1 - Abstract The intent of this thesis is to evaluate the differences in facial morphology of children between 3 and 15 years of age based on 3D facial models and cross-sectional data. Due to improper use of cross-sectional data for studying growth, the next part of the thesis is focused on the comparison of cross-sectional and longitudinal approaches in research. The longitudinal observation of facial developmental changes can be considered as actual growth. The cross-sectional database contains 839 3D facial models (397 boys, 442 girls). Three previously published longitudinal databases were used for comparison. Their age intervals were as follows: 3 to 6 years (12 boys, 14 girls), 6 to 12 years (15 boys, 18 girls), 12 to 15 years (23 boys, 22 girls). Geometric morphometric methods were used to analyse facial models (Coherent Point Drift - Dense Correspondance Analysis, Per Vertex T-Test and Principal Component Analysis). The results were visualized using superimposition colour maps, shell distance significance maps and their interlacing. When annual consecutive age intervals were used for cross-sectional data, we could not observe the fluency of differences in facial morphology between age categories, which we can observe during actual growth. When wider age intervals were used for cross-sectional...
|
guest ::
