Summary: | Transposons are a diverse collection of mobile genetic elements and are important components of nearly every genome. Because of their mobile and repetitive nature, transposons can have considerable effects on host gene expression, genome organization and evolution. The recent availability of genomic sequence information has expedited the discovery and study of transposons, as exemplified in this thesis by the complete genome analysis of the model plant system Arabidopsis thaliana. Data mining in Arabidopsis has revealed a rich diversity of transposons, of which Basho and Terminal-repeat Retrotransposons In Miniature (TRIM) elements were previously unknown types. The identification of Related to Empty Sites (RESites) provide evidence for past transposition events. Examples of elements contributing to coding regions, acquiring cellular sequences, along with in-depth analysis of the insertions, their target sites and their distribution illustrate the impact of transposons on gene and genome structures. Computer-based searches of genomic sequences has also improved our understanding of previously identified transposon families, such as the origin, classification and mobilization of Tourist elements. In addition, information on transposons gathered from in silico analysis of genomic sequences has served to design in vivo experiments. In a whole genome strategy, Transposon Display was used to investigate transposition and regulation of mobility of Tourist-like elements in A. thaliana and in the nematode Caenorhabditis elegans.
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