Kommata Vasiliki, Dermon Catherine R
Lab Human & Animal Physiology, Dept. Biology, Univ. Patras, Patras, Greece.
Lab Human & Animal Physiology, Dept. Biology, Univ. Patras, Patras, Greece.
Int J Dev Neurosci. 2018 Apr;65:11-20. doi: 10.1016/j.ijdevneu.2017.10.003. Epub 2017 Oct 13.
Complex morphogenetic events, critical for the development of normal cerebellum foliation and layering, are known to involve type III intermediate filament protein such as vimentin expressed by Bergmann glia. The present study aimed to determine aspects of intermediate and late embryonic pattern of vimentin expression during the corticogenesis of chicken cerebellum at embryonic days 10-19 (E10-E19), using single and double immunohistochemistry/immunofluorescence. Vimentin expression showed partial co-localization with the glial markers GFAP and BLBP. Within cerebellar cortex, vimentin+ fibers were first found within lobules I and X (E10) and gradually extended to all folia (E15-E17), located within the external granule (EGL) the molecular cell layer, showing a radial orientation towards the inner granular layer and the cerebellar white matter oriented longitudinally. Interestingly, within the immature fissures base of most lobules, vimentin+ fibers radiate in a fan shape. Short-term BrdU experiments revealed that EGL cell proliferation was higher in the fissure base compared to folia apex. In addition, following 24-h survival, BrdU+ cells were found in close association to vimentin+ fibers in the EGL pre-migratory zone and within immature molecular layer. Paralleling cerebellum development, vimentin expression gradually extended to all folia sub-regions (base, wall, apex), but, at day E19, it was mainly confined to the folia apex and secondary fissure base. Taken together our data further support the possible role of vimentin+ fibers in the structural events of cerebellum corticogenesis, suggesting the participation of radial/Bergmann glia in chicken cerebellum foliation, similarly to that described for mammalian cerebellum morphogenesis.
复杂的形态发生事件对于正常小脑叶片形成和分层发育至关重要，已知其涉及III型中间丝蛋白，如伯格曼胶质细胞表达的波形蛋白。本研究旨在利用单重和双重免疫组织化学/免疫荧光技术，确定鸡胚第10 - 19天（E10 - E19）小脑皮质发生过程中波形蛋白表达的胚胎中期和晚期模式。波形蛋白表达与胶质细胞标志物GFAP和BLBP部分共定位。在小脑皮质内，波形蛋白阳性纤维首先在小叶I和X中发现（E10），并逐渐扩展到所有小叶（E15 - E17），位于外颗粒层（EGL）和分子细胞层，呈朝向内颗粒层的放射状排列，且纵向朝向小脑白质。有趣的是，在大多数小叶的未成熟裂沟底部，波形蛋白阳性纤维呈扇形放射状。短期BrdU实验表明，与小叶顶端相比，裂沟底部的EGL细胞增殖更高。此外，在24小时存活期后，在EGL迁移前区和未成熟分子层中发现BrdU阳性细胞与波形蛋白阳性纤维紧密相关。与小脑发育并行，波形蛋白表达逐渐扩展到所有小叶亚区域（底部、壁、顶端），但在E19天时，它主要局限于小叶顶端和次级裂沟底部。综合我们的数据进一步支持了波形蛋白阳性纤维在小脑皮质发生结构事件中的可能作用，表明放射状/伯格曼胶质细胞参与鸡小脑叶片形成，类似于哺乳动物小脑形态发生中所描述的情况。
