Etv5 Is Required for Proper Maturation and Dendritic Development of Adult‐Born Granule Cells in the Dentate Gyrus

Adult neurogenesis in the dentate gyrus (DG) of the hippocampus is a dynamic and tightly regulated process that is finely regulated by a diverse array of transcription factors. While the transcription factor Etv5, a member of the Erythroblast Transformation Specific (ETS) family, has been implicated in embryonic development by regulating cell proliferation and differentiation across various tissues, its specific role in adult hippocampal neurogenesis remains unexplored. Here, we show that conditional ablation of Etv5 specifically in adult‐born granule cells (GCs) increases the proportion of Doublecortin (DCX)‐positive immature GCs at the expense of mature neurons, without affecting the proportion of neither radial glia‐like cells (RGCs) nor SOX2 + progenitor cells within the neurogenic niche. Furthermore, Etv5 conditional mutant mice exhibit reduced dendritic complexity and defects in spine development, indicating impaired neuronal maturation and suggesting deficits in synaptic integration of adult‐born GC neurons.