Development
Author: Caterina Laura Sister | Email: cate.sister@gmail.com
Caterina Sister1°, Guillermo Lanuza1°
1° Fundación Instituto Leloir
Astrocytes are involved in the maintenance and regulation of neurological functions and their impairment is related to several pathologies. While neuronal subtype specification is well understood, how development shapes astrocytic diversity remains unclear. Here we show that distinct dorso-ventral progenitor domains of the mouse neural tube (identified by Nkx6.1, Pax3/6/7, Dbx1, Ascl1) produce astrocyte subsets that colonize precise regions of the spinal cord. Each population, despite its origin, exhibits heterogeneity in distribution and morphology comprising gray matter (GM) protoplasmic, white matter (WM) fibrous and subpial astrocytes. We traced individual progenitor cells linage using GlastCreER mice in combination with conditional reporter lines (Tomato or GFP) or the mosaic analysis with double markers clonal system to determine if GM and WM cells share a common ventricular cell origin. Fate mappings at clonal density showed isolated astrocytes, produced by direct differentiation, or pairs of cells with identical subtype identity. Furthermore, experiments indicate that these couples are the result of symmetrical division taking place close to their final settling location after migration. In summary, this study delineates basic principles of astrocyte diversity during development. While dorso-ventral allocation maps depend on progenitor positional identity, GM and WM astrocytes seem to originate from distinct lineages within each embryonic domain.