CONICET | Buscador de Institutos y Recursos Humanos

"Astrocytic subtype specification? Evidence from developmental genetics in the embryonic neural tube" Micaela Sartoretti, Guillermo Lanuza In spite of the great progress made in the understanding of the ontogenetic mechanisms that control neuronal specification, much less is known about the origin of astrocytic subtype diversity. In this work, we begun to test the hypothesis that astrocytic subtypes specification follows similar logic that the acquisition of neuronal cell identity (dorso-ventral organization). We have focused on a small group of neural tube progenitors -termed p0- that express the transcription factor Dbx1, which are known to give rise to V0 neurons. In performing genetic cell fate mappings, we identified that these neuroepithelial cells contribute also to a group of laterally migrating cells. Marker expression analysis (NFIA, Sox9/2, GFAP) revealed that they are a subset of astrocytes that restrictively migrate along the spinal cord sulcus limitans. Interestingly, we found that in Dbx1 mutant mice, there is an increased number of p0-derived astrocytes, suggesting that Dbx1 directly or indirectly controls gliogenesis. We provide evidence that the genetic mechanism of Dbx1 involves modulation of Notch signaling pathway, by determining the class of Notch ligand (Delta/Jagged) that mediates cell-cell interactions controlling differentiation.