Distribution of Neural/Stem Progenitor Cells in the Brain of the Leopard Gecko ( Eublepharis macularius )

Endogenous neural stem/progenitor cells (NSPCs) have been identified across vertebrate species. Among adult mammals, NSPCs are spatially restricted to just two neurogenic regions: the subventricular zone of the lateral ventricle, and the subgranular zone of the hippocampal dentate gyrus. In other species – including teleost fish and urodeles – NSPCs are known to have a much broader distribution. For reptiles, less is known. Here we identify NSPCs along the rostral caudal axis of the brain of the leopard gecko ( Eublepharis macularius ; hereafter, ‘gecko’). The ventricular system of the gecko brain is bordered by a distinct neurogenic niche, the ventricular zone (VZ). All VZ cells (including those of the lateral, third and fourth ventricles) constitutively express the hallmark transcription factor of stemness, SOX 2. Additionally, VZ cells have a radial‐like morphology and pattern of protein expression (including immunostaining for the intermediate filaments Vimentin and glial fibrillary acid protein [GFAP]) closely comparable to mammalian embryonic radial glial cells. At the level of the cerebellum, putative NSPCs (SOX2+ and GFAP+) were also identified independent of the ventricular system. Proliferating cells (identified by phosphorylated histone H3 expression) are most abundant in the VZ of the lateral ventricle and cerebellar parenchyma. The VZ of the third ventricle demonstrates a comparatively modest level of proliferation, while the VZ of the fourth ventricle is largely quiescent. The presence of NSPCs, both dormant and constitutively active, across the lizard brain offers compelling evidence for its neurogenic and possibly regenerative capacity. Support or Funding Information Natural Sciences and Engineering Research Council Discovery Grant 400358