Interrelation of EAST-Dependent and Su(Hw)-Dependent Repression in Transgenic Lines of Drosophila melanogaster

Abstract

In D. melanogaster, the nuclear matrix protein EAST functionally interacts with the Su(Hw)-dependent insulator complex. The y² allele, in which the MDG4 retrotransposon is inserted between enhancers and the gene promoter, was previously described. The Su(Hw) insulator sequence is present in the regulatory region of MDG4. An increase in the EAST protein concentration or inactivation of the Mod(mdg4)-67.2 protein, which is part of the Su(Hw)-dependent complex, results in tissue-specific repression of the yellow gene in the y² allele. In the present work, the degree of EAST-dependent and Su(Hw)-dependent repression in different regions of the genome was analyzed using transposition of transgenes containing long terminal repeat (LTR) sequences of the MDG4 retrotransposon and the Su(Hw) insulator. As a result of genetic experiments, it was shown for the first time that EAST-dependent repression of the yellow gene is observed in the same transgenic lines of D. melanogaster as Su(Hw)-dependent repression. The obtained data confirm our earlier suggestion that the regulatory complex, which is formed on the LTR sequence and functionally interacts with the EAST protein, transfers the transgene to the nucleus regions with a high concentration of factors that repress transcription.