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Studium funkce AtAFB4
Zelinka, Radim
Despite the fact, that research on apical dominance started before more than 100 years ago, this economically important phenomenon is not fully understood yet. One of the genes involved in this regulation in the model plant Pisum sativum is PsMS2, that was cloned recently and it came out i tis an ortholog of the auxin F-box receptor AtAFB4. The aim of this bachelor thesis was to prepare hybrids of the Arabidopsis mutant afb4 with plants expressing the GFP gene for green fluorescent protein fused to genes of the PIN family (1,2,3,4,7) under native promoters. T1 plans from all five crosses were test-ed preliminary using the selection gene for resistance to the herbicide sulphadiazine contained in the genome of male plants and more than 50 % of T1 plants from all lines survived without any symptoms of damage. In further cultivation of the surviving plants strong phenotype resembling the afb4 mutation of the male plants was observed in all plants. From the above-mentioned facts we can conclude that we have obtained hybrids bearing the intended genetic information. These prepared plants will be used in further studies on the influence of the afb4 mutation on the changes of PIN membrane transporters and further characteristics, like changes in auxin transport, reaction to exogenous application of auxin and strigolactone, etc.
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Impact of the mode of RNAi induction on silencing of the reporter GFP gene in Arabidopsis thaliana
Růžičková, Adéla ; Fischer, Lukáš (advisor) ; Moravec, Tomáš (referee)
RNA interference (RNAi) is one of the key mechanisms that are involved in many biological processes such as control of plant gene expression, influence on chromatin arrangement or providing protection against invasive DNA or RNA transposons, viruses and transgenes. In plants, RNAi is triggered by double stranded RNA (dsRNA) that is cleaved by DICER LIKE (DCL) proteins to small RNAs (sRNAs). The size of these sRNAs is in range of 21 - 24 nucleotides (nt). Small RNA acts in the place of origin and they are also a mobile signal which in plants can move to a short distance through plasmodesmata and to a long distance trough phloem. sRNA and Argonaute (AGO) protein form RNA-induced silencing complex (RISC). Together, they recognize the target RNA molecule and contribute to an efficient RNAi phase which may be exhibited by gene silencing at posttranscriptional level (PTGS) or transcriptional level (TGS). The purpose of this study was to compare the effects of silencing constructs, witch in a controlled way differently trigger RNAi directed against the expression of the GFP reporter gene in the model organism Arabidopsis thaliana. Silencing constructs were placed under an inducible promoter activated by the presence of 17-β-estradiol (XVE system). They differed in the way of the dsRNA formation and in the...
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The influence of RDR6 activity and mode of RNAi induction on dynamics and mechanism of silencing of the reporter GFP gene in tobacco cell line BY-2
Motylová, Šárka ; Fischer, Lukáš (advisor) ; Kovařík, Aleš (referee)
RNA interference (RNAi) is a process mediated by small RNAs (sRNA), which is significantly involved in the regulation of gene expression in plants. Diverse RNAi pathways can be divided into two basic mechanisms, which are post-transcriptional and transcriptional gene silencing (PTGS and TGS). Production of sRNAs is dependent on the presence of a double-stranded RNA molecule (dsRNA), which is cleaved by one of DCL proteins to produce sRNAs usually of 21-24 nt in length. One strand of the sRNA is subsequently loaded onto AGO protein. During PTGS, the AGO-sRNA complex interacts with the target RNA based on its sequence complementarity to the sRNA and cleaves it or blocks its translation. In the case of TGS, AGO interacts with plant-specific RNA Pol V and its transcripts, which are again complementary to the sRNA. This interaction allows assembling of a protein complex facilitating DNA and histone methylation inhibiting RNA Pol II transcription. There are numerous ways the dsRNA can arise. A significant part of dsRNA cell production is dependent on synthesising the complementary strand of the dsRNA by RDR6 (RNA-dependent RNA polymerase 6). RDR6 is also involved in the process of the secondary sRNA formation. The significance of RDR6 during PTGS was examined using a GFP reporter gene either during...
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Organization and mobility of G protein-coupled receptors in plasma membrane
Merta, Ladislav ; Svoboda, Petr (advisor) ; Sýkora, Jan (referee)
This diploma thesis deals with the analysis of structural and dynamic organization of thyrotropin releasing hormone receptor (TRH-R) and δ-opioid receptor (DOR) within plasma membrane (PM) in relation to the specific sub-compartments of PM denominated as domains or membrane rafts. Modern fluorescence microscopy techniques FLIM, FRAP and RICS were used for this purpose. The experiments were performed on the live cells derived from HEK293 cell line. To reach the main goal of this work, the integrity of PM structure was altered by depletion of cholesterol which was performed by incubation of cells with β cyclodextrin. Results clearly support our previously suggested idea that the vast majority of TRH-R is localized in non-raft regions of plasma membrane. This work also compared different modes of performance of FRAP and results obtained by FRAP and RICS because these methods are to some extent analogous. This is one of the first works that used the RICS approach to characterize the G protein-coupled receptors. In the second part of this work, the setup of transient transfection of the HEK293 cells with DOR-ECFP and DOR EYFP constructs was established. Simultaneously, the functionality of these constructs, i.e. the ability of DOR to activate the cognate G protein was determined. Powered by TCPDF (www.tcpdf.org)
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Study of properties of voltage membrane sensor ASAP1 expressed in HEK293 cell line
Jablonská, Dominika ; Čmiel, Vratislav (referee) ; Svoboda, Ondřej (advisor)
This thesis deals with the problematice of measuring membrane potential and monitoring the propagation of electrical activity of cells. For this purpose, fluorescence membrane voltage sensors have been developed to detect changes in the membrane potential by changing their fluorescence intensity. The practical part is focused on the study of the properties of the ASAP1 fluorescence probe, which was transfected into the HEK293 cell line, which are kidney cells from the human embryo. Cell membrane potential was changed using the patch-clamp technique.
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Expression of genes for the conversion of nitriles and amides in Rhodococcus erythropolis
Kracík, Martin ; Pátek, Miroslav (advisor) ; Mikušová, Gabriela (referee)
The strain Rhodococcus erythropolis A4 is a source of enzymes nitrilhydratase and amidase, that catalyse conversion of nitriles and amides. These enzymes are used in industrial biotransformation and bioremediation. Since it was difficult to carry out genetic manipulations aimed at increasing the production of these enzymes in the strain A4, the corresponding genes (ami and nha1 + nha2) of a related strain R. erythropolis CCM2595, in which both plasmid and chromosome manipulations can be routinely performed, were identified and analyzed in this diploma theses. The ami and nha1 + nha2 genes from the strain R. erythropolis CCM2595 were isolated and sequenced together with the flanking regions (5.5 kb in total). The organization of these genes and the expected regulatory genes was described in the strain CCM2595 and mechanisms of regulation of expression of these genes were studied. For the analysis of transcription of amidase and nitrilhydratase genes from both strains of R. erythropolis, the promoter-probe vector pEPR1 replicating in Escherichia coli and R. erythropolis was used. Transcriptional fusion of Pami promoters of the strains A4 and CCM2595 and the reporter gfp gene were constructed. The activity of the Pami promoter was measured by means of fluorescence of gfp gene product (green fluorescent...
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Optimization of Culture Medium for HEK293 Cell Line
Čuperková, Romana ; Vaněk, Ondřej (advisor) ; Šácha, Pavel (referee)
HEK293 is a human cell line derived from embryonic kidney cells and is a frequently used system for the production of recombinant proteins. This work dealt with optimization of the composition of serum-free medium for HEK293S and HEK293T cell lines as a compensation for expensive commercial media. The growth of culture and expression of reporter proteins SEAP and GFP was monitored as the markers. I managed to create a new medium which contained, among other compounds, insulin (1 mg/l), transferrin (5 mg/l) and a mixture of trace elements. During the cultivation in a mixture of commercial medium EX CELL 293 with my new medium 293S cells grew faster than during the cultivation in commercial media (doubling time 20,47 ± 2,68 hours (srel = 13,1 %)). It seems that the new medium is suitable for transfection of HEK293 cell lines with a relatively high expression of recombinant proteins. Transfection ratio of DNA:PEI (w/w) for this medium is 1:2 to 1:3.
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Sex in Trypanosomatids
Kvapilová, Kateřina ; Volf, Petr (advisor) ; Čepička, Ivan (referee)
3 Abstrakt Rody Leishmania a Trypanosoma jsou původci vážných lidských onemocnění: leishmaniózy a trypanosomózy. Dlouhá léta nebyly u těchto parazitů nalezeny přesvědčivé důkazy o genetické výměně, a proto byly rody Trypanosoma a Leishmania považovány za klonálně se rozmnožující, a to binárním štěpením jako většina prvoků. Výzkum ztěžovaly i skutečnosti, že pohlavní dimorfismus není patrný a chromosomy nekondenzují, tudíž nejsou viditelné. Nicméně klonální model začaly zpochybňovat pozorování přirozeně se vyskytujících hybridních druhů. Nejdříve byla existence sexu popsána u trypanosom a to prvním přímým důkazem hybridů T. brucei, získaných po společném přenosu rodičů mouchou tsetse. U leishmanii byl důkaz poskytnut na základě dvojitě rezistentních hybridů a sexuální výměna podstupovala stejný meiotický proces jako T. brucei. Byli pozorovaní přirozeně se vyskytující hybridi Nového i Starého světa jak u rodu Viannia, tak i u rodu Leishmania. Otázkou dalších výzkumů bylo, jaký je mechanismus genetické výměny, ale odpověď dodnes není jasná. Klíčová slova: genetická výměna, Trypanosoma, Leishmania, klonalita, meióza, GFP, přenašeč Abstract Genera Leishmania and Trypanosoma are agents of serious human diseases: leishmaniasis and trypanosomózy. For many years these parasites were considered clone-replicating by...
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