The role of transposons in the structural evolution of eukaryotic genomes

Abstract

We presented evidence of the role of transposons in the occurrence of centromeric repeats in plants and animals. During evolution, transposable elements are retained as part of centromeres and participate in interaction with kinetochore. Moreover, the centromere protein CENP-B, telomerase and telomeres were derived from transposons. For the functioning of centromeres, the necessary role of RNA interference was proved. Non-coding RNAs that are processed from centromere transcripts are involved in this process. We assume that this property was acquired due to the protective mechanisms of the hosts against transposons, which have been successfully used for the regulation of genomes. As a result, the universal mechanism of chromosomes during mitosis was formed for all eukaryotes, since transposons play a global role in the structural and functional regulation of genomes. Evolutionary kinship of transposons with viruses, which are characterized by interactions with microtubule tubulin, is proved. Moreover, bacteriophages encode tubulin-like PhuZ protein. In evolution, spliceosomal introns, epigenetic and transcription factors and their binding sites, non-coding RNAs and many protein-coding genes have evolved from transposons. These facts indicate the evolutionary formation of a complex system of regulation of cell functions involving transposons and the role of transposons in the structural evolution of genomes.