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Silencing of Transposable Elements in Plants and Implications for Rationalised Transgene Design
Tobiáš, Andrej ; Fischer, Lukáš (advisor) ; Moravec, Tomáš (referee)
(English) Transposable elements (TEs) are integral parts of all plant genomes. Their ability to change their position (transpose) or copy to a new position and induce mutations within these genomes has driven evolution for billions of years. Despite its importance, unrestrained transposition can lead to irreversible genomic damage. Therefore, plants have evolved special silencing mechanisms to regulate transposition and "silence" TEs. This allows plants to harness the mutagenic potential of TEs, tame their new insertions, and thus potentially acquire genomic novelties. Silencing mechanisms operate mostly at the epigenetic/transcriptional level, where they induce methylation on target DNA or histones. This accounts for RNA-dependent DNA methylation pathways (RdDMs). Additionally, they operate at the post-transcriptional level, where they degrade target mRNA through a pathway known as post-transcriptional gene silencing (PTGS). These silencing mechanisms have also become proficient in recognizing both natural and artificial transgenes. Recognition and subsequent silencing of transgenes diminishes the efficiency of transgenesis and, thus, successful production of genetically modified organisms (GMOs). Extensive research into these silencing pathways and TEs can lead to a better understanding of what...
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