| Popis: |
We study highly abundant chromoviral Tekay clade in species from three sister genera – Anemone, Pulsatilla and Hepatica of the Ranunculaceae family. With this clade we perform a concomitant survey of its phylogenetic diversity, chromosomal organisation and transcriptional activity in Anemone s.l. in order to investigate the dynamics of the Tekay elements at a finer scale than previously achieved in this or any other flowering clade. A phylogenetic tree built from Tekay sequences does not conform to expected evolutionary relationships of the species, and we invoked the horizontal transfer to explain the observed topology. The separation of the elements within six clades could be explained by episodic bursts of activity since divergence from a common ancestor, at different points in their respective evolutionary histories. In Anemone s.l. the Tekay elements do not have preferential position on chromosomes, meaning that they can have: i) centromeric/pericentromeric position ; ii) interstitial position in DAPI positive AT-rich heterochromatic regions ; or even iii) absent from large heterochromatic blocks ; or they can be vi) dispersed throughout chromosomes. Widespread transcriptional activity of the Tekay elements in Anemone s.l. taxa indicate that some copies of Tekay elements could be still active in this plant group contributing to the genome evolution and speciation within the Anemone s.l. |
