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Methanogenic symbionts of Psalteriomonadidae (Heterolobosea: Tetramitia)
Foučková, Martina ; Čepička, Ivan (advisor) ; Steinová, Jana (referee)
Psalteriomonadidae is a small family of anaerobic amoeboflagellates belonging to Heterolobosea. So far, 16 species have been described and there are also at least another 17 putative species which are yet to be formally described. Their anaerobic lifestyle is associated with a modification of the mitochondria into hydrogen-producing hydrogenosomes. The main focus of this thesis is on methanogenic symbionts of this family. The presence of prokaryotic symbionts has been observed in three species of Psalteriomonas, namely P. lanterna, P. vulgaris and P. magna. In P. lanterna, and P. vulgaris the symbionts were identified as Methanobacterium formicicum on the basis of their morphology and biochemical properties. For this thesis, 37 new freshwater isolates of psalteriomonadids were collected, identified, sequenced, and together with older isolates in culture, were investigated for the presence of prokaryotic symbionts. The UV autofluorescence of the symbionts of P. lanterna P. magna and Psalteriomonadidae sp. 5 indicates that they are methanogenic Archaea. No traces of methanogens were found in three isolates of Sawyeria marylandensis and three isolates of different Harpagon species. The symbionts were identified as Methanoregula sp. based on the 16S rRNA gene sequence. The symbionts were divided into...
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Utilization of Biology Olympiad in schools and implementation of selected tasks into highschool teaching.
Dvořáková, Darina ; Janštová, Vanda (advisor) ; Drda Morávková, Alena (referee)
This thesis deals with the Biology Olympiad and remaking of selected tasks of region round. The remaked tasks can be used in highschool education. The thesis includes theoretical and practical part. The theoretical part provides general information about the Biology Olympiad (BiO), charts the achievements of Czech students in International Biology Olympiad (IBO), includes literary review of selected topics. The practical part encompass four remaked tasks of different topics: Eucaryotic cell as a mosaic, Water in life of animals, Animals' areas and their distribution, History of the flora in Czech Republic. The tasks are processed in the form of worksheets. The worksheets were tested at schools. Knowledge of students was tested by using of created pretests and posttests. The practical part also presents the result of research based on a questionnaire survey focused on the involvement of school in BiO and teachers' opinions on these topics.
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Losses of mitochondria and plastids in the evolution of eukaryotes
Trokšiar, David ; Hampl, Vladimír (advisor) ; Hadariová, Lucia (referee)
- 5 - Abstract: Mitochondria and plastids were acquired by endosymbiotic event, where prokaryotic organism was engulfed by ancestors of extant eukaryotes. There are more known endosymbiotic events in plastid evolution. In primary endosymbiosis cyanobacterium cell was engulfed by heterotrophic eukaryotic organism. In following secondary, tertiary and quaternary endosymbiotic events eukaryotic cell was engulfed by another eukaryote. Mitochondria originated by engulfment of α-proteobacteria. In the evolution of eukaryotes, reduction of mitochondria occurred in many lineages, making living under anaerobic conditions possible. The least reduced form is anaerobic mitochondria, which together with aerobic mitochondria and hydrogen producing mitochondria, possess genome. Hydrogenosomes and the most reduced form mitosomes, does not possess genome. Plastid reductions led to loss of photosynthetic ability. In last years, more examples of organisms that lost entirely their semi- autonomous organelle, are coming. Loss occur at two parasitic representatives of the Alveolata group, and one endobiotic oxymonad. Parasites Cryptosporidium parvum and Hematodinium lost nonphotosyntetic plastid, whereas Monocercomoides lost its mitochondria. Semi-autonomous organelles were dispensable, because all representatives have access to...
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Structure and function of mitochondrial secretin.
Klápšťová, Veronika ; Doležal, Pavel (advisor) ; Pyrih, Jan (referee)
Type II secretion system (T2SS) is one of the secretion systems found in gram-negative bacteria that provides transport of some bacterial proteins across the outer membrane. The passage through the membrane is mediated by a pore assembled from subunits called GspD or secretin. Together with three other components of T2SS, GspD was discovered in the genome of several protists including Naegleria gruberi, Andalucia godoyi, Reclinomonas americana, Neovahlkampfia damariscottae or in s species of genus Malawimonas. Previously it was found out that these proteins localize into the mitochondria. If found functional and with analogous topology to the bacterial system, the eukaryotic T2SS would represent unique mitochondrial protein export system. Secretin is essential subunit of T2SS which is not only the passive membrane channel, but also participates in the recognition of the substrate. Therefore, the research of the eukaryotic secretin could bring a valuable knowledge about the function of the mitochondrial T2SS. The experimental part of this thesis tries to characterize the eukaryotic secretin and it focuses on (i) the assembly of the secretin channel, in both, the bacteria and in the artificial membranes, (ii) the interactions of GspD with the other subunits of T2SS and (iii) the mechanism of import...
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Utilization of Biology Olympiad in schools and implementation of selected tasks into highschool teaching.
Dvořáková, Darina ; Janštová, Vanda (advisor) ; Drda Morávková, Alena (referee)
This thesis deals with the Biology Olympiad and remaking of selected tasks of region round. The remaked tasks can be used in highschool education. The thesis includes theoretical and practical part. The theoretical part provides general information about the Biology Olympiad (BiO), charts the achievements of Czech students in International Biology Olympiad (IBO), includes literary review of selected topics. The practical part encompass four remaked tasks of different topics: Eucaryotic cell as a mosaic, Water in life of animals, Animals' areas and their distribution, History of the flora in Czech Republic. The tasks are processed in the form of worksheets. The worksheets were tested at schools. Knowledge of students was tested by using of created pretests and posttests. The practical part also presents the result of research based on a questionnaire survey focused on the involvement of school in BiO and teachers' opinions on these topics.
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