Jourdon Alexandre, Gresset Aurélie, Spassky Nathalie, Charnay Patrick, Topilko Piotr, Santos Renata
Ecole Normale Supérieure, PSL Research University, CNRS, Inserm, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), 46 rue d'Ulm, 75005, Paris, France.
UPMC Univ Paris 06, IFD, Sorbonne Universités, 4 Place Jussieu, 75252, Paris Cedex 05, France.
Brain Struct Funct. 2016 Dec;221(9):4411-4427. doi: 10.1007/s00429-015-1171-z. Epub 2015 Dec 23.
Adult neurogenesis in the mammalian brain is restricted to specific regions, such as the dentate gyrus (DG) in the hippocampus and the subventricular zone (SVZ) in the walls of the lateral ventricles. Here, we used a mouse line carrying a knock-in of Cre recombinase in the Prss56 gene, in combination with two Cre-inducible fluorescent reporters (Rosa26 and Rosa26 ), to perform genetic tracing of Prss56-expressing cells in the adult brain. We found reporter-positive cells in three neurogenic niches: the DG, the SVZ and the hypothalamus ventricular zone. In the prospective DG, Prss56 is expressed during embryogenesis in a subpopulation of radial glia. The pattern of migration and differentiation of reporter-positive cells during development recapitulates the successive steps of DG neurogenesis, including the formation of a subpopulation of adult neural stem cells (NSC). In the SVZ, Prss56 is expressed postnatally in a subpopulation of adult NSC mainly localized in the medial-ventral region of the lateral wall. This subpopulation preferentially gives rise to deep granule and Calbindin-positive periglomerular interneurons in the olfactory bulb. Finally, Prss56 is also expressed in a subpopulation of α2-tanycytes, which are potential adult NSCs of the hypothalamus ventricular zone. Our observations suggest that some α2-tanycytes translocate their soma into the parenchyma and may give rise to a novel cell type in this territory. Overall, this study establishes the Prss56 line as an efficient and promising new tool to study multiple aspects of adult neurogenesis in the mouse.
成年哺乳动物大脑中的神经发生仅限于特定区域，如海马体中的齿状回（DG）和侧脑室壁中的室下区（SVZ）。在此，我们使用了一种在Prss56基因中携带Cre重组酶敲入的小鼠品系，结合两种Cre诱导型荧光报告基因（Rosa26 和 Rosa26 ），对成年大脑中表达Prss56的细胞进行遗传追踪。我们在三个神经发生微环境中发现了报告基因阳性细胞：DG、SVZ和下丘脑室周区。在未来的DG中，Prss56在胚胎发育期间在放射状胶质细胞的一个亚群中表达。发育过程中报告基因阳性细胞的迁移和分化模式概括了DG神经发生的连续步骤，包括成年神经干细胞（NSC）亚群的形成。在SVZ中，Prss56在出生后主要定位于外侧壁内侧腹侧区域的成年NSC亚群中表达。这个亚群优先产生嗅球中的深颗粒和钙结合蛋白阳性的球周中间神经元。最后，Prss56也在α2-伸展细胞的一个亚群中表达，α2-伸展细胞是下丘脑室周区潜在的成年NSC。我们的观察结果表明，一些α2-伸展细胞将其胞体转移到实质中，并可能在该区域产生一种新的细胞类型。总体而言，本研究将Prss56 品系确立为研究小鼠成年神经发生多个方面的一种有效且有前景的新工具。
