Arkhipova 96-29741 Research Planning Grant Abstract This project focuses on a Drosophila melanogaster moderately repetitive retrotransposon, mdg1, with an exceptionally complex promoter, the activity of which can be changed during development of the fly. A novel aspect which has never been observed in vitro is its duel specificity for RNA polymerase II/III (pol II/III). The generality and the basis of this phenomenon need be investigated but preliminary studies are needed to define the two possible origins of pol II/III transcripts of the retrotransposon and to detect any variation in transcripts during the development of the fly. These results will allow further research in one of two alternate directions. %%% Participation of mobile DNA in the organization and function of eukaryotic genomes remains a subject of controversy. However it is beginning to be recognized that many different roles might be played in various processes at the cellular, organismic and population levels by different transposons. Transposons share the corresponding machinery with many host genes and their ability to multiply can lead to multiplication of regulatory elements found in the transposons. Therefore, a knowledge of the diverse regulatory sequences carried by transposons, such as promoters, could result in understanding of transposon involvement into qualitative as well as quantitative aspects of regulatory evolution in higher eukaryotic organisms.
