Proliferating neuronal progenitors in the postnatal hippocampus transiently express the proneural gene Ngn2.
Little is known of the transcription factors expressed by adult neural progenitors produced in the hippocampal neurogenic niche. Here, we study the expression of the proneural basic helix-loop-helix (bHLH) transcription factor Neurogenin-2 (Ngn2) in the adult hippocampus. We have characterized the pattern of expression of Ngn2 in the adult hippocampus using immunostaining for Ngn2 protein and a Ngn2-green fluorescent protein (GFP) reporter mouse strain. A significant proportion of Ngn2-expressing cells were mitotically active. Ngn2-GFP expression was restricted to the subgranular zone and declined with age. Neuronal markers were used to determine the phenotype of Ngn2-expressing cells. The vast majority of Ngn2-GFP-positive cells expressed the immature neuronal markers, doublecortin (DCX) and polysialic acid-neural cell adhesion molecule (PSA-NCAM). Finally, the pattern of Ngn2 expression was studied following seizure induction. Our data show an increase in neurogenesis, detected in these animals by bromodeoxyuridine (BrdU) and DCX staining that was contemporaneous with a marked increase in Ngn2-GFP-expression. Taken together, our results show that Ngn2-GFP represents a specific marker for neurogenesis and its modulation in the adult hippocampus. Ngn2 transient expression in proliferating neuronal progenitors supports the idea that it plays a significant role in adult neurogenesis.
Ozen
Ilknur
I
Department of Clinical Neurosciences, University of Cambridge, Robinson Way, Cambridge, UK.
Galichet
Christophe
C
Watts
Colin
C
Parras
Carlos
C
Guillemot
François
F
Raineteau
Olivier
O
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D001973:Bromodeoxyuridine; D002454:Cell Differentiation / Q000235:genetics; D049109:Cell Proliferation; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D049452:Green Fluorescent Proteins; D006624:Hippocampus / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D007150:Immunohistochemistry; D051379:Mice; D008822:Mice, Transgenic; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D039842:Neural Cell Adhesion Molecule L1 / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism; D012640:Seizures / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D012794:Sialic Acids / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*
D051792:Basic Helix-Loop-Helix Proteins; D015415:Biomarkers; D001973:Bromodeoxyuridine; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D049452:Green Fluorescent Proteins; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D039842:Neural Cell Adhesion Molecule L1; D009479:Neuropeptides; D012794:Sialic Acids; C000714847:Dcx protein, mouse; C102938:Neurog2 protein, mouse; C103469:polysialyl neural cell adhesion molecule