[Expression of homologous and heterologous retrotransposons in a model system of yeast cells].

Yeast cells Saccharomyces cerevisiae were transformed by the recombinant plasmids containing the Yeast retrotransposon Ty and the Drosophila mobile element gypsy under the control of a strong Yeast promoter. The exogenous Ty-element induces the complete cycle of Ty-retrotransposition including the TyRNA synthesis, formation of virus-like particles, synthesis of all reverse transcriptase intermediates in the virus-like particles with the subsequent circles formation and transposition. The Drosophila mobile element gypsy is capable of inducing the formation of the virus-like particles containing RNA, DNA and proteins of the Ty-retrotransposon only. The Ty-circles and induction of transposition were not observed. The obtained data demonstrates the existence of the multistep repression system for Ty-transposition cycle. The possibility and efficiency of using the model to study the mechanism for retrotransposon transposition is discussed.