Zebrafish Neurogenetics Department, Helmholtz Zentrum München, German Research Center for Environmental Health, D-85764 Neuherberg, Germany.
J Comp Neurol. 2011 Jun 15;519(9):1748-69. doi: 10.1002/cne.22599.
All subdivisions of the adult zebrafish brain maintain niches of constitutive neurogenesis, sustained by quiescent and multipotent progenitor populations. In the telencephalon, the latter potential neural stem cells take the shape of radial glia aligned along the ventricle and are controlled by Notch signalling. With the aim of identifying new markers of this cell type and of comparing the effectors of embryonic and adult neurogenesis, we focused on the family of hairy/enhancer of split [E(spl)] genes. We report the expression of seven hairy/E(spl) (her) genes and the new helt gene in three neurogenic areas of the adult zebrafish brain (telencephalon, hypothalamus, and midbrain) in relation to radial glia, proliferation, and neurogenesis. We show that the expression of most her genes in the adult brain characterizes quiescent radial glia, whereas only few are expressed in progenitor domains engaged in active proliferation or neurogenesis. The low proliferation status of most her-positive progenitors contrasts with the embryonic nervous system, in which her genes are expressed in actively dividing progenitors. Likewise, we demonstrate largely overlapping expression domains of a set of her genes in the adult brain, which is in striking contrast to their distinct embryonic expression profiles. Overall, our data provide a consolidated map of her expression, quiescent glia, proliferation, and neurogenesis in these various subdivisions of the adult brain and suggest distinct regulation and function of Her factors in the embryonic and adult contexts.
成年斑马鱼大脑的所有细分区域都维持着组成性神经发生的龛位，这是由静止和多能祖细胞群体维持的。在端脑中，后者潜在的神经干细胞呈现出沿脑室排列的放射状胶质的形状，并受 Notch 信号的控制。为了鉴定这种细胞类型的新标志物，并比较胚胎和成年神经发生的效应物，我们专注于 hairy/enhancer of split [E(spl)] 基因家族。我们报告了 7 个 hairy/E(spl)（her）基因和新的 helt 基因在成年斑马鱼大脑的三个神经发生区域（端脑、下丘脑和中脑）中的表达，与放射状胶质、增殖和神经发生有关。我们表明，成年大脑中大多数 her 基因的表达特征是静止的放射状胶质，而只有少数基因在参与活跃增殖或神经发生的祖细胞区域表达。大多数 her 阳性祖细胞的低增殖状态与胚胎神经系统形成鲜明对比，在胚胎神经系统中，her 基因在活跃分裂的祖细胞中表达。同样，我们证明了一组 her 基因在成年大脑中的表达区域大部分重叠，这与它们在胚胎中的不同表达模式形成鲜明对比。总的来说，我们的数据提供了成年大脑各区域中 her 表达、静止胶质、增殖和神经发生的综合图谱，并表明 Her 因子在胚胎和成年环境中的调节和功能存在明显差异。
