Transposition ofSaccharomyces CerevisiaeTy1 Retrotransposon Depends on the Function of Mitochondria

Ty1 is a mobile genetic element (transposon) which is transposed spontaneously with a frequency rate of about 1×10−7/element/generation. It was found recently that carcinogens can induce Ty1 transposition to about 1×10−6/element/generation. While molecular background of the spontaneous Ty1 transposition is studied in details, the mechanism of carcinogen induced Ty1 transposition is not known. We found that mitochondrial functions participate in Ty1 transposition. The carcinogen induced Ty1 transposition can not take place in cells with dysfunctional mitochondria (rho− mutants) or cells which fulfill their energy requirement on glycolysis. Contrary to this, the rate of spontaneous Ty1 transposition in mitochondrial mutants is increased. The obtained results suggest the existence of different mechanisms for spontaneous and carcinogen induced transposition of the Ty1 retrotransposon.