Berrebi A S, Oberdick J, Sangameswaran L, Christakos S, Morgan J I, Mugnaini E
Laboratory of Neuromorphology, University of Connecticut, Storrs 06269-4154.
J Comp Neurol. 1991 Jun 22;308(4):630-49. doi: 10.1002/cne.903080409.
Previous studies have been directed at the elucidation of neuron-specific gene expression in the mammalian central nervous system. In particular, we have identified a series of marker molecules that are expressed in cerebellar Purkinje cells with varying degrees of specificity. Here, we show by light microscopic immunocytochemistry and Northern transfer and hybridization that two of these markers, namely, L7 and PEP19, are expressed in the retina of mouse and rabbit, while a third marker, cerebellin, is absent. Light and electron microscopic immunocytochemistry proves that L7-like immunoreactivity is restricted to rod bipolar cells, while PEP 19-like immunoreactivity is distributed in both rod and cone bipolars. PEP19 is also expressed by subsets of amacrine and ganglion cells. The density of PEP19-positive bipolar cells is greater than that of L7-positive bipolar cells, although the density of each is approximately equal in central and peripheral portions of the retina. An antiserum to a fourth Purkinje cell marker, vitamin D-dependent calcium-binding protein-28 kD (CaBP), reveals primarily axonless horizontal cells, but also subsets of rod bipolar, amacrine, and, in the mouse but not in the rabbit, ganglion cells. The processes of immunoreactive cell bodies form discrete bands in the internal plexiform layer, and mixtures of the antisera help distinguish their identity. Thus, these Purkinje cell markers can be used at the electron microscopic level to unravel the extremely complex neuropil of this retinal layer. Furthermore, knowledge of the retinal distribution of this panel of molecules is of general value for future studies of retinal neuronal typology and can serve to map the densities of subsets of bipolar cells throughout the retina. The expression of L7 and PEP19 in bipolar cells and in Purkinje cells suggests a biochemical relationship between these two spatially distant neuronal populations.
以往的研究致力于阐明哺乳动物中枢神经系统中神经元特异性基因的表达。特别是，我们已经鉴定出一系列标记分子，它们在小脑浦肯野细胞中以不同程度的特异性表达。在此，我们通过光学显微镜免疫细胞化学、Northern印迹转移和杂交表明，其中两个标记分子，即L7和PEP19，在小鼠和兔子的视网膜中表达，而第三个标记分子小脑素则不存在。光学和电子显微镜免疫细胞化学证明，L7样免疫反应性仅限于视杆双极细胞，而PEP19样免疫反应性分布在视杆和视锥双极细胞中。PEP19也由无长突细胞和神经节细胞的亚群表达。PEP19阳性双极细胞的密度大于L7阳性双极细胞的密度，尽管两者在视网膜中央和周边部分的密度大致相等。针对第四个浦肯野细胞标记分子维生素D依赖性钙结合蛋白-28 kD（CaBP）的抗血清主要揭示无轴突水平细胞，但也揭示视杆双极细胞、无长突细胞以及在小鼠而非兔子中的神经节细胞的亚群。免疫反应性细胞体的突起在内部丛状层形成离散带，抗血清混合物有助于区分它们的身份。因此，这些浦肯野细胞标记分子可用于电子显微镜水平，以揭示该视网膜层极其复杂的神经毡。此外，了解这组分子在视网膜中的分布对于未来视网膜神经元类型学的研究具有普遍价值，并且可用于绘制整个视网膜双极细胞亚群的密度图。L7和PEP19在双极细胞和浦肯野细胞中的表达表明这两个在空间上相距遥远的神经元群体之间存在生化关系。
