A Homeobox Transcription Factor Scarecrow (SCRO) Negatively Regulates Pdf Neuropeptide Expression through Binding an Identified cis -Acting Element in Drosophila melanogaster

AbstractInDrosophila, transcriptional feedback loops contribute to intracellular timekeeping mechanisms responsible for daily rhythms. Pigment-dispersing factor (PDF) is the major neuropeptide produced by latero-ventral neurons (LNvs) that function as a central pacemaker for circadian locomotor activity rhythms. PDF synchronizes other clock neurons thereby playing an essential role in the maintenance and coordination of circadian locomotor rhythms. However, the underlying molecular mechanism of the LNvs-specificPdf expression is not well understood. Here, usingPdf promoter-bashing experiment, we identified acis-actingPdf regulatory element (PRE) that is sufficient for drivingPdf expression in the LNvs. We have also identified a homeobox transcription factor, scarecrow (SCRO), as a direct binding factor toPRE. Furthermore, transgenic expression ofscro in the clock neurons abolishedPdf expression and circadian locomotor activity rhythms, and such repressive function requires DNA-binding homeodomain, but none of the other conserved domains.scro is predominantly expressed in the optic lobe and various clusters of cells in other areas of the central nervous system. A homozygousscro-null mutant generated by CRIPSR is lethal during embryonic and early larval development, suggesting thatscro plays a vital role during early development.

Source: Molecular Neurobiology - January 15, 2020 Category: Neurology Source Type: research