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Are there any temperature related changes in morphological integration of Micrasterias cells?
Buchtová, Edith ; Neustupa, Jiří (advisor) ; Kleisner, Karel (referee)
Micrasterias rotata is a phylogenetically and morphologically well defined species that is widely distributed in Central Europe in a broad temperature gradient. For its complex cell shape Micrasterias rotata is a suitable model organism for cell morphogenesis research. This thesis investigated whether there could be a different pattern in morphological integration resulting from the temperature stress in Micrasterias rotata cells cultivated on a temperature gradient. The optimum and a limits of growth on the temperature gradient were related to the sampling locations of the studied strains isolated from a lowland wetland and an high alpine lake. Differences in the growth rates among the strains suggested a local adaptation to the climatic conditions of the original locations but relatively high values of the assumed optimum growth temperature suggested an intra- species evolutionary adaptation. The temperature-related size reduction rule was not confirmed; however, a similar pattern of variation in shape occurred in both strains. The morphological integration analysis has basically confirmed that the Micrasterias cell is composed of a number of morphological modules related to its differentiation into the lobes and sublobes. Integration between the lobes of the opposite semicell was primarily...
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Stress induced morphogenic response in plant root system
Otradovcová, Michala ; Soukup, Aleš (advisor) ; Vaňková, Radomíra (referee)
The root system architecture adjustment is one of the possible plant reactions to stress effects of environmental conditions. The shape of root system is jointly formed by the root apical meristem activity, the rate of elongation of root cells and by the degree of formation, developement and organization of secondary and adventitious roots. This paper aims to describe basic mechanisms of the root system developement and outline the morphological and regulatory changes occuring during development while being affected by selected stress factors.
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The influence of postural ontogenesis on morphological development of trunk
Hladíková, Veronika ; Kobesová, Alena (advisor) ; Šafářová, Marcela (referee)
This bachelor thesis engages in an influence of postural ontogenesis on formation of anatomical structures of trunk. Postural ontogenesis depends on maturation of the central nervous system, which stimulates automatic, accurately timed recruitment of muscles to posture. At the same time with postural muscle activation, morphogenesis of the skeleton is finishing. As a consequence of abnormal motor development, there are deviations in bone shape and in setting of joints. The thesis is focused on the description of a morphological development of spinal curves, thorax and abdominal wall. The development of cervical lordosis and the shape of the upper part of thorax is linked to the development of motor functions of upper limbs. The significant milestone is an ability to lift and hold head above the surface in prone position. The development of lumbar lordosis and the shape of the lower part of thorax is determined by motor functions of lower limbs, which are firstly manifested by lifting lower limbs in supine position. The development of sitting, stance and gait plays a crucial role. The development of abdominal wall is assessed by presence, or rather absence of diastasis recti abdominis, which is related to the quality of muscle coordination in this area. Practical part of the thesis devotes to...
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Diversity, distribution, phylogeny and ecology of the genus Micrasterias (Desmidiales)
Trumhová, Kateřina ; Šťastný, Jan (advisor) ; Bestová, Helena (referee)
The genus Micrasterias comprises one of the most beautiful organisms. It attracts, due to its spectacularly shaped cells, the attention of scientist and amateur biologist almost for almost 200 years. This thesis summarizes the current knowledge about these extraordinary organisms. The first part deals with the morphology and the life cycle of these algae. They share a unique type of reproduction (conjugation) with the other representatives of the class Zygnematophyceae. The second part concerns phylogeny of this genus. Several morphologically distinct species have been revealed with the aid of molecular phylogenetic methods to belong to the genus Micrasterias. A polyphasic evaluation of three species complexes within this genus also revealed an extensive hidden diversity. The last chapters summarize the knowledge about the influence of hidden diversity and accelerated morphological evolution on our understanding of diversity and biogeography of these organisms.
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Role of cytoskeleton in plant cell morphogenesis
Miklánková, Pavlína ; Schwarzerová, Kateřina (advisor) ; Sekereš, Juraj (referee)
The cells are able to acquire variety of shapes, in which cytoskeleton plays an important role. Cytoskeleton influences deposition of cell wall materials, regulates vesicle movement in cell, participates in exocytosis and endocytosis. Cortical microtubules affect celulose accumulation in cell wall and determine direction of cell expansion, although the exact connection between microtubules and cellulose remains unclear. Actin promotes growth and contributes to its spatial regulation in both tip ang diffuse growing cells. Actin is important for secretion in expanding cells but its exact functions in cell growth regulation are not explained yet. Analysis of mutants, spectroscopic methods, cytoskeletal drugs, fluorescence proteins and other methods are used to better understand how actin and microtubule cytoskeleton are integrated during plant cell morphogenesis. Epidermal and trichome cells of Arabidopsis thaliana are a good model of research and they are used for most studies.
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Morfogeneze orálního skeletu mihule ve vztahu k evoluci čelistí
Romášek, Marek ; Černý, Robert (advisor) ; Jandzík, Dávid (referee)
4 Neural crest-derived cellular cartilage is one of the defining characteristics of vertebrates. Elaboration of this tissue and its patterning allowed the evolution of jaws in the gnathostome lineage. Together these hallmarks helped jawed vertebrates become one of the dominant taxons in the animal kingdom. Lampreys, as basal jawless vertebrates, lie at a unique phylogenetic position that makes them ideal organisms for the study of evolution of vertebrate/gnathostome novelties. Larval lampreys possess a special oral skeleton composed of a tissue related to cartilage, termed mucocartilage. Despite considerable attention that has been paid to the evolutionary significance of mucocartilage, it is not yet clear, how this unique feature arises in development and to what extent it is homologous to gnathostome jaws. In this study, the development of oro-pharyngeal region was analyzed in the sea lamprey Petromyzon marinus. SEM imaging revealed shaping and topographic relationships of embryonic tissues, detailed plastic histology coupled with expression analyses of several molecular markers were used to describe origin, histogenesis and morphogenesis of mucocartilage. Furthermore, genetic regulation of the tissue was investigated in order to identify its unique or shared features. Mucocartilage is seen to...
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Ontogeny of exaggerated structures in dung beetles (Coleoptera: Scarabaeinae)
Žídek, Radim ; Hanus, Robert (referee) ; Šípek, Petr (advisor)
E n g l i s h a b s t r a c t Horns of scarab beetles represent a secondary sexual characters present mostly in males, to whom they serve as weapons in combats over the acces to females. In many species, two discrete male forms occur, "horned" and "hornless", which employ different reproductive strategies. Adult body size and horn morphology are determined by nutritional conditions encountered by larvae during their development. Switching between developmental pathways is accomplished by circulating levels of juvenile hormone (JH) which reflect body size, and genetically determined threshold of sensitivity to it. When body size is larger then threshold, horn growth occur, whereas if it's not, a brief pulse of ecdysone reprogramme the development and hornless adult emerge. Reprogramming the development encompass modifications of the insulin receptor pathway as well as changes in exact domains of genes expression envolved in specifying the proximodistal axis of the developing horn. Development of horns is morphologically reminiscent that of other insect appendages, with which it shares the expression of genes wingless, decapentaplegic, Distal-less, dachshund, homothorax, aristaless and EGFR, parts of gene regulatory network ensuring origin of the outgrowth of the cuticle. Some of them are expressed through...
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Morphogenesis and growth of the benthic water bug (\kur{Aphelocheirus aestivalis }(Fabricius, 1794) (Insecta: Heteroptera: Aphelocheiridae).
INDROVÁ, Eliška
INDROVÁ E. 2008: Development and growth of the benthic water bug (Aphelocheirus aestivalis (Fabricius, 1794) (Insecta: Heteroptera: Aphelocheiridae). MSc. Thesis, University of South Bohemia, Pedagogical Faculty, České Budějovice. 62 pp. Postembryonic morphogenesis of the benthic water bug (A. aestivalis) was studied. Morphometric characters were measured in specimens of population from the Dračice River (South Bohemia: Třeboňsko). Differential characters of individual developmental stages are described and illustrated. Growth of this species is characterised by diagrams and equations of selected body parametres.
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