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Development and dynamics of the palatal and pharyngeal dentition in sterlet
Novotná, Štěpánka ; Soukup, Vladimír (advisor) ; Oralová, Veronika (referee)
Dentition is a key vertebrate innovation showing not only great morphological diversity, but also different maintenance or replacement of functional teeth. Most extant vertebrates replace their dentition through addition of new teeth from deeply invaginated epithelium, i.e. the successional dental lamina, due to presence of dental stem cells. However, in some early branching lineages of ray-finned fishes (Actinopterygii), new tooth germs arise from the adjacent superficial epithelium without the presence of the successional dental lamina. Whether the two types of dental development in vertebrates are equivalent and whether comparable dental stem cells play role in tooth replacement is currently not satisfactorily evaluated. This Master thesis aims at describing the development of palatal and pharyngeal dentition of a member of an early branching lineage of ray-finned fishes, the sterlet sturgeon (Acipenser ruthenus). The sterlet dentition is fairly dynamic. The teeth are replaced without the successional dental lamina, however, this replacement shows characteristics similar to those described in vertebrates with the successional dental lamina. A marker of dental stem/progenitor cells, Sox2, is localized in the outer dental epithelium of the predecessor tooth in the vicinity of the adjacent taste...
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Dynamic and role of cytosekeletal proteins in mammalian sperm cells
Paleček, J. ; Dvořáková, K. ; Pěknicová, Jana ; Kubátová, Alena ; Dráber, Pavel
The cytoskeleton of sperm head consists of resistant structural proteins of the nucleus and of perinuclear theca, which are largely rosponsible for the shaping of the nucleus. three mahjor cyteskeletal proteins, actin, tzubnulin and spectrin, are present in the head of mammalian spermatohzoa. Maoreober, the mictotubular cytoskeleton also contains other dynamic proteins, which have a morphological function within the cell and which are responsible for cell signalling processes.
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