A single DPE core promoter motif contributes toin vivotranscriptional regulation and affects cardiac function

Abstract

AbstractTranscription is initiated at the core promoter, which confers specific functions depending on the unique combination of core promoter elements. The downstream core promoter element (DPE) is found in many genes related to heart and mesodermal development. However, the function of these core promoter elements has thus far been studied primarily in isolated,in vitroor reporter gene settings.tinman(tin) encodes a key transcription factor that regulates the formation of the dorsal musculature and heart. Pioneering a novel approach utilizing both CRISPR and nascent transcriptomics, we show that a substitution mutation of the functionaltinDPE motif within the natural context of the core promoter results in a massive perturbation of Tinman’s regulatory network orchestrating dorsal musculature and heart formation. Mutation of endogenoustinDPE reduced the expression oftinand distinct target genes, resulting in significantly reduced viability and an overall decrease in adult heart function. We demonstrate the feasibility and importance of characterizing DNA sequence elementsin vivoin their natural context, and accentuate the critical impact a single DPE motif has duringDrosophilaembryogenesis and functional heart formation.