[Induction of transcription through the scs insulator leads to abnormal development of Drosophila melanogaster].

A regulatory element named scs is one of the first insulators discovered in Drosophila, which was found on the boundary of the hsp70 domain. The 993-bp scs insulator contains two promoters at the ends and two polyadenylation signals located in the same orientation in the central part of the insulator. In the Drosophila transgenic lines, induction of a strong transcription through the scs insulator only in the direction that coincides with the direction of the two polyadenylation sites activity results in multiple phenotypic defects of the Drosophila development and embryonic lethality. A similar effect was not observed upon testing of other known Drosophila insulators.

[Organization of the Drosophila melanogaster SF1 insulator and its role in transcription regulation in transgenic lines].

The SF1 insulator was found to contain a polyadenylation signal, which corresponded to the functional polyadenylation signal in embryonic S2 cells and the transgenic lines of Drosophila and bi-directional promoter that functioned in S2 cells. The studies performed did not confirm the ability of the SF1 insulator to protect expression of reporter gene white from the chromosome position effect in transgenic lines.

[Functional interactions between promoters of neighboring yellow and CG3777 genes in Drosophila melanogaster].

It was shown by us previously that the transcription of the yellow gene can be affected by the promoter of the neighboring gene CG3777, which has a similar expression profile. In the present work, we continued studying the functional interactions between the promoters of the yellow and CG3777 genes in transgenic Drosophila strains. In this work, we used the failure of the yeast activator GAL4 to stimulate transcription from the promoter of the yellow gene for the case when GAL4-binding sites are localized at the 3'-end of the gene. It has been found that, if the 983-bp CG3777 gene promoter is inserted in transgenic strains in the same orientation with the yellow gene promoter, downstream from the sites of the GAL4 activator, the CG3777 promoter provides a strong stimulation of the yellow gene by the GAL4 activator. When the promoters of the yellow and CG3777 genes are inserted in opposite orientations relative to one another, no stimulation of the yellow gene by GAL4 is observed. Additional results obtained in the work demonstrate that the functional interacton between the CG3777 and yellow promoters depends on their mutual orientation and position relative to the GAL4-binding sites.