Cortical upper layer neurons derive from the subventricular zone as indicated by Svet1 gene expression.
Cortical upper layer neurons derive from the subventricular zone as indicated by Svet1 gene expression.
复制标题
DOI：
--
复制
发表时间：
2001-06
期刊：
影响因子：
4.6
通讯作者：
Victor Tarabykin;Anastassia Stoykova;Natalia Usman;Peter Gruss
中科院分区：
文献类型：
--
作者：
Victor Tarabykin;Anastassia Stoykova;Natalia Usman;Peter Gruss
大脑皮层由大量不同类型的神经元组成。除部分中间神经元外，所有皮层神经元均生于两个增殖区，即皮层脑室区（VZ）和脑室下区（SVZ）。两个增殖区对皮层神经元多样性产生的相对贡献尚不清楚。为了进一步剖析潜在的机制，需要SVZ特异性的分子标记。为此，我们对从E15.5和E18.5小鼠大脑皮层生成的cDNA文库进行了减法。克隆了一种新的cDNA Svet1，它在SVZ的增殖细胞中特异性表达，而在VZ中不表达。VZ以Otx1基因的表达为标志。在发育后期，Svet1和Otx1分别在上层（II-IV）和深层（V-VI）细胞亚群中表达。在卷叶皮层中，层是倒置的，Svet1和Otx1分别在它们的新位置标记上层和深层的前体。有趣的是，在Pax6/小眼突变体中，SVZ和皮层板上部的Svet1活性被取消，而Otx1表达域保持不变。因此，使用Svet1和Otx1作为皮层上层和深层的细胞类型特异性分子标记，我们得出结论，Sey突变主要影响无法迁移到皮层板的SVZ细胞的分化。SVZ的异常与皮层上层细胞的缺失相吻合。综上所述，我们的数据表明，虽然深部皮质层的规范发生在心室区，但SVZ对于上层的适当规范很重要。
The cerebral cortex is composed of a large variety of different neuron types. All cortical neurons, except some interneurons, are born in two proliferative zones, the cortical ventricular (VZ) and subventricular (SVZ) zones. The relative contribution of both proliferative zones to the generation of the diversity of the cortical neurons is not well understood. To further dissect the underlying mechanism, molecular markers specific for the SVZ are required. Towards this end we performed a subtraction of cDNA libraries, generated from E15.5 and E18.5 mouse cerebral cortex. A novel cDNA, Svet1, was cloned which was specifically expressed in the proliferating cells of the SVZ but not the VZ. The VZ is marked by the expression of the Otx1 gene. Later in development, Svet1 and Otx1 were expressed in subsets of cells of upper (II-IV) and deep (V-VI) layers, respectively. In the reeler cortex, where the layers are inverted, Svet1 and Otx1 label precursors of the upper and deeper layers, respectively, in their new location. Interestingly, in the Pax6/small eye mutant, Svet1 activity was abolished in the SVZ and in the upper part of the cortical plate while the Otx1 expression domain remained unchanged. Therefore, using Svet1 and Otx1 as cell-type-specific molecular markers for the upper and deep cortical layers we conclude that the Sey mutation affects predominantly the differentiation of the SVZ cells that fail to migrate into the cortical plate. The abnormality of the SVZ coincides with the absence of upper layer cells in the cortex. Taken together our data suggest that while the specification of deep cortical layers occurs in the ventricular zone, the SVZ is important for the proper specification of upper layers.