Genome dynamics

     The emerging paradigm represents a genome as a very dynamic system generating its own rearrangements where mostly transposable elements but also (micro)satellites and promiscuous DNA are the key players. Recent studies showed that epigenetics can shape dynamics of transposable elements thus responding to environmental changes.

     We study behavior of transposable elements and other dynamic genome components like microsatellites and promiscuous DNA in non-recombining Y chromosome. We mostly use model plant species – Silene latifolia, Rumex acetosa, Hippophae rhamnoides possessing evolutionarily young sex chromosomes. We study structural features, genomic proportions, activity, regulation and epigenetic silencing of transposable elements. We combine experimental and bioinformatic approaches.

     We have found that some transposable elements accumulate on the Y chromosome as a result of recombination absence while others are lacking there probably because they jump only in female individuals. We have revealed that silencing of some LTR retrotransposon in males was ensured by small RNAs. Microsatellites, representing another dynamic component of genomes, have often expanded on the Y chromosome of Silene latifolia and Rumex acetosa.  We also study mechanisms of formation and turnover of promiscuous DNA - plastid and mitochondrial DNA transferred into nucleus and proposed a model of their insertion close to centromeres and subsequent movement further along chromosomal arms. Our studies on regulation of transposable elements showed that quadruplex DNA inhibits an activity of transposable elements.