The role of Scabrous in long distance Notch signaling during bristle patterning
Authors: Adam Presser; Ginger Hunter
Affiliation: Clarkson University
Keywords: q. epithelial sheets; d. Notch
Correctly ordered thoracic bristles are necessary for the fly to effectively sense its environment. Notch signaling is critical for the patterning of these bristles: cells in the developing notum epithelium self-organize into Delta-expressing bristle precursor cells and Notch-activated epithelial cells. In order to maintain wildtype bristle spacing, long-distance signaling is necessary. This can occur via either filopodia-mediated Notch signaling or paracrine signaling by diffusible Notch regulators. Scabrous is a secreted protein expressed in bristle precursor cells, and the dynamics of Scabrous signaling in live notum are under-characterized. Based on the literature, we hypothesized that Scabrous acts as a positive regulator of Notch signaling at a distance. Furthermore that Scabrous activity is independent of filopodia-mediated, long-range Notch signaling. Here, we describe several aspects of Scabrous signaling including the location of Scabrous within the patterning tissue using live confocal imaging of Drosophila pupae and fluorescence-stained, dissected pupal nota. We also analyze Notch signaling in response to changes in Scabrous expression levels. These data will help to improve current models of tissue patterning driven by Notch-mediated lateral inhibition.