(161s) Dynamic Gene Control through Interallelic Interactions in Drosophila Embryos

The mechanism of which enhancers interact with the target promoter to initiate transcription has been extensively studied. However, recent studies suggest that the 3D genome organization also plays an important role in gene regulation. We use live imaging methods and quantitative analysis in living Drosophila embryos to show that interallelic interactions can affect transcriptional dynamics. We find that homologous alleles interfere with each other when one allele has only a partial transcription unit. For example, when one allele has an intact cis-linked enhancer and the target promoter while the other allele has an enhancer or a promoter-reporter gene cassette only, mRNA production from the intact enhancer-promoter allele was reduced. We propose that the allelic interactions may occur through clusters of transcription factors and mediator+Pol II complexes, and transcriptional machineries are shared between two alleles to result in reduced transcriptional activity.