Abstract
In many vertebrates, establishment of Left-Right (LR) asymmetry results from the activity of a ciliated organ functioning as the LR Organizer (LRO). While regulation of the formation of this structure by major signaling pathways has been described, the transcriptional control of LRO formation is poorly understood. Using the zebrafish model, we show that the transcription factors and cofactors mediating or regulating the transcriptional outcome of the Hippo signaling pathway play a pivotal role in controlling the expression of genes essential to the formation of the LRO including ligands and receptors of signaling pathways involved in this process and most genes required for motile ciliogenesis. Moreover, the transcription cofactor, Vgll4l regulates epigenetic programming in LRO progenitors by controlling the expression of writers and readers of DNA methylation marks. Altogether, our study uncovers a novel and essential role for the transcriptional effectors and regulators of the Hippo pathway in establishing LR asymmetry.