Dr. Priscilla Valentino
Postdoctoral Fellow, University of Toronto Mississauga, Erclik Lab
PI: Prof. Ted Erclik
12 to 1 PM
IB 140 & Zoom
Title
Patterning neural progenitors through space and time in the Drosophila optic lobe
Abstract
The temporal and spatial patterning of neural stem cells is a powerful mechanism by which to generate neural diversity. In the Drosophila optic lobe, the neuroblasts (NBs) that generate the ~150 neuronal cell types of the medulla are patterned by independent temporal and spatial inputs. In the temporal axis, a cascade of transcription factors (TFs) is expressed in medulla NBs as they age. In the spatial axis, the neuroepithelium from which these NBs are generated is compartmentalized by the expression of additional TFs and signaling molecules. Distinct neuronal types are generated by NBs based on their spatio-temporal address. We have found that a third major patterning axis further diversifies neuronal fates in the medulla. We show that the symmetrically dividing neuroepithelial cells from which the NBs are generated are temporally patterned by opposing gradients of the Imp and Syp RNA-binding proteins. Imp and Syp regulate the expression of the Chinmo, Mamo and E93 TFs in the neuroepithelium to confer NBs from the same spatio-temporal address with unique identities based on the developmental stage in which they are generated. As a proof of principle, we demonstrate that Imp and Syp differentially pattern NBs in the Vsx1-Hth spatio-temporal birth window to generate seven distinct neuronal types (Li2, TmY17, TmY15, Tm23, Pm3a, Pm3b, and TmY12) in successive developmental windows over the course of the three days of medulla neurogenesis. We further demonstrate that the developmental birthdate of these Vsx1-Hth neurons correlates with their final position in the adult cortex, resulting in unanticipated specializations of the retinotopic circuit in the anterior-posterior axis.
Visit Dr. Valentino's ResearchGate page to read her publications!