Elmquist J K, Swanson J J, Sakaguchi D S, Ross L R, Jacobson C D
Department of Veterinary Anatomy, Iowa State University, Ames 50011.
J Comp Neurol. 1994 Jun 8;344(2):283-96. doi: 10.1002/cne.903440209.
Cells of glial origin are involved in the morphogenesis of the mammalian central nervous system (CNS). Characterization of glial-associated proteins during neurogenesis and differentiation may aid in understanding the complexity of CNS development. We have utilized immunoblotting and immunohistochemistry to characterize the developmental profiles of glial fibrillary acidic protein (GFAP) and vimentin (VIM) in the brain of the Brazilian opossum, Monodelphis domestica. Typical of marsupials, CNS morphogenesis and neurogenesis in the opossum extend well into the postnatal period. Opossum GFAP and VIM were found as single bands at molecular weights consistent with those reported for other species, thus indicating conservation of the VIM and GFAP proteins through mammalian evolution. Differential developmental trends were observed for both proteins with relative VIM levels decreasing and GFAP levels increasing with age. Vimentin-like immunoreactivity (VIM-IR) was present at day 1 of postnatal life throughout the brain. The density of VIM-IR was maximal at 10 and 15 days postnatal (especially in radial glial elements) and decreased slightly by 25 days postnatal. In the adult brain, VIM-IR was markedly reduced compared to that of younger ages. In contrast, GFAP-like immunoreactivity (GFAP-IR) in the brain of Monodelphis increased dramatically with age. No GFAP-IR was observed in the 1 and 5 day postnatal brains. By 25 days postnatal, the pattern of GFAP-IR in the brainstem resembled that of the adult. In the forebrain, more GFAP-IR was present than at younger ages. The adult distribution of GFAP-IR was very similar to that reported for other mammalian species. These results indicate that GFAP and VIM are reciprocally related during periods of morphogenesis and differentiation of the opossum brain.
神经胶质起源的细胞参与哺乳动物中枢神经系统（CNS）的形态发生。在神经发生和分化过程中对神经胶质相关蛋白进行表征，可能有助于理解中枢神经系统发育的复杂性。我们利用免疫印迹和免疫组织化学方法，对巴西负鼠（Monodelphis domestica）大脑中胶质纤维酸性蛋白（GFAP）和波形蛋白（VIM）的发育情况进行了表征。负鼠作为有袋类动物的典型代表，其中枢神经系统的形态发生和神经发生会一直持续到出生后很长一段时间。发现负鼠的GFAP和VIM呈现为单一条带，其分子量与其他物种报道的一致，这表明VIM和GFAP蛋白在哺乳动物进化过程中具有保守性。观察到这两种蛋白呈现出不同的发育趋势，随着年龄增长，VIM的相对水平下降，而GFAP水平上升。出生后第1天，整个大脑都存在波形蛋白样免疫反应性（VIM-IR）。VIM-IR的密度在出生后10天和15天达到最大值（特别是在放射状胶质细胞成分中），到出生后25天时略有下降。在成年大脑中，与较年轻个体相比，VIM-IR明显减少。相比之下，Monodelphis大脑中的胶质纤维酸性蛋白样免疫反应性（GFAP-IR）随年龄显著增加。在出生后第1天和第5天的大脑中未观察到GFAP-IR。到出生后25天时，脑干中GFAP-IR的模式类似于成年个体。在前脑中，GFAP-IR比年轻个体时更多。GFAP-IR在成年个体中的分布与其他哺乳动物物种报道的非常相似。这些结果表明，在负鼠大脑的形态发生和分化阶段，GFAP和VIM呈相互关联的关系。
