发育过程中Pax6基因的表达以及小鼠大脑皮质片层化的形成

Pax6 expression in the brain and cortical lamination in developing mouse

目的：研究大脑新皮质发育过程中Pax6的表达模式以及片层化的形成特点。方法：应用石蜡切片技术、免疫荧光等技术对胚胎和出生后小鼠（E15-P90）进行研究。结果：Pax6基因在小鼠大脑内的表达起始于胚胎时期，表达在室管下层干细胞内，随着年龄的增长，干细胞开始分化为神经元，新生神经元向皮质边缘迁移，最终形成皮质板，Pax6的表达也随之迁移，且表达量逐渐减少。Foxp2最早出现在纹状体，随后强烈表达在皮质板（第Ⅴ-Ⅵ层）。结论：Pax6基因与大脑皮质的形成以及神经干细胞的发生有关。Foxp2可作为神经元的一种标记物，特异性的标记新皮质第Ⅴ-Ⅵ层神经元。标记显示小鼠大脑新皮质片层化的过程先后经历细胞增殖、分化、迁移过程，同时还伴随着皮质板锥体细胞的成熟。

Objective： To observe Pax6 expression patterns and the cortical lamination during the neocortical development. Methods： With the paraffin sections, the immunofluorescence assay technologies were carried out in embryonic and postnatal mice from El5 - P90. Results： Pax 6 gene expression in the mouse brain started at the embryonic period, and expressed in the stem cells of subventricular zone. With age increasing, stem cells began to spread and differentiate into neurons. Eventu- ally the newborn neurons from the stem cells formed into the cortical plate. Finally, Pax6 expression gradually decreased and almost disappeared in adult. It was also confirmed that Foxp2 was associated with the formation of mouse neocortex, espe- cially the neurons in subplate （future layer Ⅴ-Ⅵ. Conclusion： Pax6 gene involves in the formation of the cerebral cortex and the histogenesis of the neural stem cells. The cortical development and lamination has gone through neural proliferation, differentiation, migration process, along with the maturity of the cortical plate pyramidal cells.