Massive loss of Cajal-Retzius cells does not disrupt neocortical layer order
Massive loss of Cajal-Retzius cells does not disrupt neocortical layer order
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DOI：
10.1242/dev.02209
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发表时间：
2006-02-01
期刊：
影响因子：
4.6
通讯作者：
Grove, EA
中科院分区：
文献类型：
--
作者：
Yoshida, M;Assimacopoulos, S;Grove, EA
Cajal-Retzius(CR)细胞是新皮质发育中卷轴蛋白的主要来源，被认为是新皮质层内向外形成所必需的。命运图显示，大量的新皮质CR细胞起源于皮质下摆。为了研究CR细胞的功能，我们因此对其进行了基因消融。新皮质CR细胞在对照组小鼠软膜下分布，但在去氢小鼠从胚胎第10.5天到出生时几乎不存在。来自其他来源的CR细胞不会侵入新皮质原基以补偿HEM的丢失。我们预测，在缺乏卷轴信号的卷轴动物中，新皮质层将会倒置，就像卷轴老鼠一样。与预期相反，层层显示出标准的顺序。皮质原基中的低水平卷曲蛋白，或从其他部位扩散的卷曲蛋白，可能使分层得以进行。然而，我们的发现表明，覆盖在新皮质原基上的富含卷轴蛋白的CR细胞片并不需要直接层序。
Cajal-Retzius (CR) cells, the predominant source of reelin in developing neocortex, are thought to be essential for the inside out formation of neocortical layers. Fate mapping revealed that a large population of neocortical CR cells arises from the cortical hem. To investigate the function of CR cells, we therefore genetically ablated the hem. Neocortical CR cells were distributed beneath the pial surface in control mice, but were virtually absent in hem-ablated mice from embryonic day (E) 10.5 until birth. CR cells derived from other sources did not invade the neocortical primordium to compensate for hem loss. We predicted that neocortical layers would be inverted in hem-ablated animals, as in reeler mice, deficient in reelin signaling. Against expectation, layers showed the standard order. Low levels of reelin in the cortical primordium, or diffusion of reelin from other sites, may have allowed lamination to proceed. Our findings indicate, however, that the sheet of reelin-rich CR cells that covers the neocortical primordium is not required to direct layer order.