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Transgene silencing in potato plants and tobacco cell line BY-2
Tyč, Dimitrij ; Fischer, Lukáš (advisor) ; Honys, David (referee)
Accidental discovery of RNA interference in plants a few decades ago and its description by Fire et al. (1998) brought a real revolution in molecular biology and in many other branches of biology. Researchers have uncovered a large and unexpected mechanism of regulation of gene expression at many levels in almost all studied eukaryotes. The first studies have revealed silencing of both exogenous and endogenous genes in plants. So, it soon became clear that this process serves to organisms not only in the defense against viruses, but also against mobile genetic elements as well as in modulation of expression own genes. The key role in all RNAi mechanisms is played by dsRNA that is processed into small RNAs. In association with a number of other proteins, small RNAs can direct either cleavage of complementary or nearly complementary mRNAs or block their translation in the process of posttranscriptional gene silencing (PTGS). Additionaly, sRNAs can affect gene expression at transcriptional level via modifying DNA in a process called RNA dependent DNA methylation (RdDM). In plant transformation, RNAi cause variability amongst transgene lines and instability in the expression of introduced genes, which complicates the use of transgenic lines, because many biotechnological approaches require a defined...
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Transgene silencing in potato plants and tobacco cell line BY-2
Tyč, Dimitrij
Accidental discovery of RNA interference in plants a few decades ago and its description by Fire et al. (1998) brought a real revolution in molecular biology and in many other branches of biology. Researchers have uncovered a large and unexpected mechanism of regulation of gene expression at many levels in almost all studied eukaryotes. The first studies have revealed silencing of both exogenous and endogenous genes in plants. So, it soon became clear that this process serves to organisms not only in the defense against viruses, but also against mobile genetic elements as well as in modulation of expression own genes. The key role in all RNAi mechanisms is played by dsRNA that is processed into small RNAs. In association with a number of other proteins, small RNAs can direct either cleavage of complementary or nearly complementary mRNAs or block their translation in the process of posttranscriptional gene silencing (PTGS). Additionaly, sRNAs can affect gene expression at transcriptional level via modifying DNA in a process called RNA dependent DNA methylation (RdDM). In plant transformation, RNAi cause variability amongst transgene lines and instability in the expression of introduced genes, which complicates the use of transgenic lines, because many biotechnological approaches require a defined...
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Study of RNAi mechanisms in tobacco BY-2 cell line and potato plants
Tyč, Dimitrij ; Fischer, Lukáš (advisor) ; Kovařík, Aleš (referee) ; Moravec, Tomáš (referee)
Knowledge of the processes of RNA interference, the regulation of gene expression by small RNAs (sRNAs), has grown at an unprecedented rate over the last 30 years. Some of the findings were literally revolutionary, as they revealed events that overturned many long-held notions. Many phenomena have been shown to be highly conserved and common to organisms of different species, but others are specific to certain lineages or have not yet been fully explored. There is also a lack of knowledge about the interconnection of numerous pathways - for example between silencing at the transcriptional (TGS, leading to the promoter methylation) and post-transcriptional levels (PTGS, affecting mRNA stability or translation). The present work summarizes the findings of two published and two unpublished works and attempts to describe some of the less known sites of RNA interference using various plant model organisms. Research on Solanum tuberosum transgenic lines has revealed the ability of 5-azacytidine to restore the expression of transcriptionally silenced transgenes at the whole plant level. De novo regeneration from leaves of such plants can lead to re-silencing of reactivated transgenes and thus serves as a selection method to exclude lines prone to spontaneous silencing. The nature of changes in the...
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Transgene silencing in potato plants and tobacco cell line BY-2
Tyč, Dimitrij
Accidental discovery of RNA interference in plants a few decades ago and its description by Fire et al. (1998) brought a real revolution in molecular biology and in many other branches of biology. Researchers have uncovered a large and unexpected mechanism of regulation of gene expression at many levels in almost all studied eukaryotes. The first studies have revealed silencing of both exogenous and endogenous genes in plants. So, it soon became clear that this process serves to organisms not only in the defense against viruses, but also against mobile genetic elements as well as in modulation of expression own genes. The key role in all RNAi mechanisms is played by dsRNA that is processed into small RNAs. In association with a number of other proteins, small RNAs can direct either cleavage of complementary or nearly complementary mRNAs or block their translation in the process of posttranscriptional gene silencing (PTGS). Additionaly, sRNAs can affect gene expression at transcriptional level via modifying DNA in a process called RNA dependent DNA methylation (RdDM). In plant transformation, RNAi cause variability amongst transgene lines and instability in the expression of introduced genes, which complicates the use of transgenic lines, because many biotechnological approaches require a defined...
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Transgene silencing in potato plants and tobacco cell line BY-2
Tyč, Dimitrij ; Fischer, Lukáš (advisor) ; Honys, David (referee)
Accidental discovery of RNA interference in plants a few decades ago and its description by Fire et al. (1998) brought a real revolution in molecular biology and in many other branches of biology. Researchers have uncovered a large and unexpected mechanism of regulation of gene expression at many levels in almost all studied eukaryotes. The first studies have revealed silencing of both exogenous and endogenous genes in plants. So, it soon became clear that this process serves to organisms not only in the defense against viruses, but also against mobile genetic elements as well as in modulation of expression own genes. The key role in all RNAi mechanisms is played by dsRNA that is processed into small RNAs. In association with a number of other proteins, small RNAs can direct either cleavage of complementary or nearly complementary mRNAs or block their translation in the process of posttranscriptional gene silencing (PTGS). Additionaly, sRNAs can affect gene expression at transcriptional level via modifying DNA in a process called RNA dependent DNA methylation (RdDM). In plant transformation, RNAi cause variability amongst transgene lines and instability in the expression of introduced genes, which complicates the use of transgenic lines, because many biotechnological approaches require a defined...
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