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Transcriptional regulation of PIN4 protein, membrane transporter of plant hormone auxin.
Hurný, Andrej ; Petrášek, Jan (advisor) ; Holá, Dana (referee)
PIN-FORMED (PIN) proteins are plant-specific secondary transporters acting in the efflux of plant signaling molecule auxin from cells. Their asymmetrical localization within cells determines the directionality of auxin flow and thereby influences plant development. The activity of PIN proteins is regulated at multiple levels; however the primary step in the regulation of PIN proteins takes place at the level of gene transcription. Therefore the main focus of this diploma thesis is the characterization of the transcriptional regulation of PIN proteins, namely PIN4 protein. The observation of plants carrying transcriptional fusion consisting of various lengths of PIN4 promoter and green fluorescent protein (GFP) showed which part of PIN4 promoter is essential for binding transcription factors and for the start of transcription. This part of PIN4 promoter was used as bait for transcription factors in yeast one hybrid screens. Altogether, 24 transcription factors were identified in which the most numerous were transcription factors from GATA and APETALA2 (AP2)/ETHYLENE RESPONSE FACTOR (ERF) families. To verify the interactions between identified transcription factors and PIN4 promoter, the protoplast transient expression assay was used. Protoplasts isolated from Arabidopsis thaliana leaves and tobacco BY-2 cell...
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Impact of the rRNA modifications on protein synthesis
Kročová, Eliška ; Pospíšek, Martin (advisor) ; Holá, Dana (referee)
A ribosome is a supramolecular structure, which mediates synthesis of all cellular proteins, and therefore is essential for cell life. The fact, that some nucleotides of ribosomal RNA are modified, is known for forty years. However only recently, successful deeper studies on how the individual modifications are synthesized and what is their effect on ribosome synthesis and function appear. Some particular nucleotide modifications are important for the ribosome formation (like m1 acp3 Ψ1191 SSU), some others influence proper function of the ribosome (e.g. Um2921, Gm2922, Ψ2923 LSU, m1 acp3 Ψ1191 SSU). Majority of modified nucleotides in eukaryotic rRNA is being recognized by small nucleolar RNA (snoRNA). Few nucleotides is, however, recognized and subsequently modified by specific proteins. These proteins also play crucial role in ribosome maturation. In thesis presented, current knowledge on the role of ribosomal RNA nucleotide modifications during their formation and maturation, and on their function is summarized and overviewed.
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Cis and trans elements in plant response to drought (with a particular focus on photosynthetic genes)
Panchártek, Daniel ; Holá, Dana (advisor) ; Feketová, Zuzana (referee)
Abiotic stresses, such as drought, high salinity and cold can strongly affect plant development and growth. Cis and trans elements are one of the options how plants regulate their own metabolism in those cases. That's the way how the expression of many target genes is induced. The products of these genes function not only in stress tolerance but also in general stress response. Many transcription factors and regulatory proteins (trans elements) are involved in these adaptions; those often interact with specific sequences in gene promoters (cis elements). Recenly, a progress has been made in analyzing the signal paths and complex cascades of gene expression regulation, although a little is still known about this regulation during drought conditions. Some of these target genes code products participating in photosyntesis and the regulation of their expression can significantly affect this process. This essay briefly describes main cis and trans elements of plant response to drought (with a particular focus on the regulation of photosyntetic genes). Keywords: drought, gene expression, cis-element, transcription factor, abcisic acid, photosyntesis, promoter.
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Molecular cytogenetic analysis of marker chromosomes and related abnormalities
Semanko, Adam ; Kočárek, Eduard (advisor) ; Holá, Dana (referee)
The primary focus of this diploma thesis is on marker chromosomes and phenotypically similar human karyotype polymorphisms, variants of short acrocentric arms in particular. The first half provides a very useful review of literature concerning different aspects of both sSMC and human polymorphisms such as their origin, inheritance, associated phenotype, formation and molecular cytogenetic methods that are applied in the process of identification of these aberrations. The methodical emphasis is on FISH and its modifications (e.g. M-FISH, acro M FISH, cen M-FISH) as well as on the CGH methods. The main objective was to test the above-mentioned methods and state their limitations and applications. Thus, in the other half we provide evaluations of commonly used methods and introduce new strategies that could be implemented to make the identification of these additional chromosomes or satellite translocations more effective. All the conclusions are based on the analysis of 7 patients with sSMC and 4 patients with variants involving acrocentric NOR regions. The results of our thorough research into their karyotypes have been compared with similar findings in the literature. Last but not least, we tried to establish a link between observed abnormalities and the type of a chromosomal aberration at hand.
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Inter- and intraspecific variability in Vicia faba L. and Zea mays L. response to water deficit
Fridrichová, Lenka ; Holá, Dana (advisor) ; Zelenková, Sylva (referee)
This work monitors the response of plants to water deficit and subsequent restoration of water availability with the aim to expand our knowledge about plant behaviour during and after drought stress from the perspective of two plant species with a different type of photosynthesis. A particular attention was paid to the intraspecific differences and their possible changes during stress and post-stress periods. The plant response was monitored as the changes of selected photosynthetic, morphological and developmental characteristics caused by the cessation of watering for six days followed by a six-day period of renewed optimal water supply. The experiments were carried out on plants with different types of photosynthesis - C3 plant Vicia faba L and C4 plant Zea mays L.; for both plant species, three varieties / genotypes were monitored. The response of both plant species to insufficient water supply differed by the extent of changes in relative water content (RWC), chlorophyll fluorescence parameters, the dry mass of individual leaves (developed during the stress period), the ratio between the aboveground dry mass and dry mass of roots. In drought-stressed plants, downward trend in RWC was observed, as well as the increase of the minimum yield of chlorophyll fluorescence in dark-adapted leaves (F ),...
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Non-coding RNA in hepresvirus infection
Pelák, Ondřej ; Holá, Dana (referee) ; Drda Morávková, Alena (advisor)
MiRNAs are endogenous short RNAs that are well conserved in eukaryotic organisms and are thought to be a vital and evolutionarily ancient component of genetic regulation. Their key role is in post-transcriptional regulation of gene expression. Some viruses were able to utilize the capabilities of these tiny RNAs to regulate their own gen expression or to regulate host gene expression in use of avoidance from immunity answers to their presence. Among these viruses belongs also the Herpesviridae family. Members of this family are using miRNA in various ways, from regulation of their own gene expression to targeting host mRNA, which prevents translation of factors related to immune answers. This work is intent on biogenesis of miRNA, its mechanism, function and manner in which it is used by representatives from Herpesviridae family.
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Genetic diversity in genes important for survival of the domestic horse
Vokatá, Barbora ; Hořín, Petr (advisor) ; Holá, Dana (referee)
Genetic diversity is important for a species and/or population survival. Diseases represent a permanent threat for domestic, captive and wild animal populations. Therefore, genetic diversity in genes involved in resistance/susceptibility to infectious and other diseases is of great interest. In this study, microsatellites and single nucleotide polymorphisms (SNPs) in immunity-related genes were used as markers to describe genetic diversity of three different breeds of the domestic horse (Equus caballus): Camargue, Murgese and Icelandic horses. 30 microsatellite and 21 SNP markers developed in this laboratory were genotyped in all three populations by using direct sequencing and PCR-RFLP techniques, respectively. Intra-population characteristics as well as genetic distances among the populations were obtained using the Arlequin3.1software. Microsatellite analysis revealed similar genetic diversity in all three populations studied. Average observed heterozygosities (Ho) ranged from 0,683 of Icelandic horse to 0,715 of Murgese and the mean number of alleles (NA) varied form 6,37 of Murgese to 7,63 of Camargue. In Icelandic horse population 13 breed-specific alleles with a frequency _ 0,2 were found, suggesting a larger genetic heterogeneity of this breed. Similarly, genetic distances represented by the FTS...
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Analysis of primary photosynthetic processes in conifers: A comparison of selected methods and their possible utilisation for the study of genetic variability
Palovská, Markéta ; Holá, Dana (advisor) ; Albrechtová, Jana (referee)
Conifers are important both ecologically and socioeconomically, however, same parts of their biology are not that well researched. This includes genetics and breeding and partly even physiology. Because quantitative genetic analyzes applied in breeding necessitate an analysis of a large number of samples, and conventional methods of analysis are quite time-consuming, certain parameters describing e.g. the activity of photosynthetic electron-transport chain (ETC) are considered for such use. Several methods of the measurement of the activity of photosynthetic ETC exist, but there are some problems with their usage in conifers. I studied this issue from different points of view in three parts of this thesis. 1) I compared the photosynthetic ETC activity in 8 species of conifers using chlorophyll (Chl) fluorescence measurements on intact needles and polarographic measurements in isolated chloroplasts. Each method brought different information. 2) I measured Chl fluorescence parameters, reflectance spectra and pigment content in 536 genetically defined trees of Pinus sylvestris L. Many parameters showed relatively high genetic variability and heritability. I have also determined the suitability of various reflectance indices to estimate pigment and water content of needles. 3) I have optimized the...
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