Transcriptional Dynamics of scylla and charybde in the Drosophila melanogaster embryo

Abstract

In complex organisms, gene regulation often involves complex enhancer-promoter interactions that are established over long distances between one or more enhancers and promoters. However, the molecular mechanisms and dynamics that foster long distance gene regulation remain unclear. Here, it is hypothesized that a recurring sequence called the GAGA sequence mediates long range promoter-enhancer interactions by helping to loop DNA. Experimentation will be based around the genes scylla and charybde as a result of the presence of GAGA sites in their promoter sequences and their participation in long range enhancer-promoter interaction performed over 235kb. In this investigation, several lines were generated to evaluate the role of GAGA elements in establishing long range interaction and observe the transcriptional dynamics of scyl and chrb. So far, it has been observed that, despite being 235 kb apart, scyl and chrb are spatially co-expressed with chrb being expressed later than scyl possibly due to a closer proximity between scyl and the enhancer than with chrb. Interestingly, when both genes are expressed in the same nucleus, transcription initiation seems to be coordinated, implying that the same enhancer is activating both genes simultaneously.