Röhlich P, Szél A, Papermaster D S
Department of Pathology, University of Texas Health Science Center, San Antonio 78284.
J Comp Neurol. 1989 Dec 1;290(1):105-17. doi: 10.1002/cne.902900107.
Immunocytochemical reactions with several antibodies to visual pigments were used to study visual cells of the Xenopus laevis retina. Monoclonal antibodies to bovine opsin "E," 1D4, and 4B4 (reactive with the N- and C-terminus and with the loop connecting transmembrane segments 5-6, respectively) and to chicken visual pigments COS-1 and OS-2 (binding to mammalian red/green and blue cones, respectively), as well as a rabbit antifrog opsin serum 11-7, were applied to semithin and thin sections of the retina. The bound antibodies were detected with the peroxidase technique at the light microscopic level; a three-stage immunogold procedure was used for electron microscopic immunocytochemistry. The overwhelming majority of rods were labeled by monoclonal antibodies "E," 4B4, 1D4, OS-2, and serum 11-7. A small fraction (2-3%) of rods did not bind monoclonal antibodies "E" and 4B4, but this minor population of rods was strongly reactive with 1D4 and to a lesser extent with OS-2, indicating the presence of different visual pigment. These rods differ in shape from the major rod type; they are thinner, shorter, and may be comparable to the blue-sensitive ("green") rods of other amphibia. Cones were morphologically heterogeneous: double cones, large single cones, and small single cones were found, and the large single and the double cones were occasionally duplicated. Double cones and large single cones (as well as their duplicated varieties) strongly bound monoclonal antibodies COS-1 and were unlabeled by all other monoclonal antibodies, except OS-2. The small single cone was remarkably unreactive with COS-1 and "E," weakly labeled by 1D4 and 4B4, and most reactive with OS-2 and 11-7. This unique pattern of immunocytochemical reactions in the small cone type indicates the uniqueness of its visual pigment from other cone types in the Xenopus retina. The present study shows the existence of two different opsins in morphologically distinct (thick and thin) rod types and at least two cone pigments in the heterogeneous cone population.
利用针对视觉色素的几种抗体进行免疫细胞化学反应，以研究非洲爪蟾视网膜的视觉细胞。使用了针对牛视蛋白“E”、1D4和4B4的单克隆抗体（分别与N端和C端以及跨膜片段5 - 6之间的环反应），以及针对鸡视觉色素COS - 1和OS - 2的单克隆抗体（分别与哺乳动物的红/绿锥和蓝锥结合），还有兔抗蛙视蛋白血清11 - 7，将其应用于视网膜的半薄切片和超薄切片。在光学显微镜水平上，用过氧化物酶技术检测结合的抗体；在电子显微镜免疫细胞化学中使用了三级免疫金程序。绝大多数视杆细胞被单克隆抗体“E”、4B4、1D4、OS - 2和血清11 - 7标记。一小部分（2 - 3%）视杆细胞不结合单克隆抗体“E”和4B4，但这一小部分视杆细胞与1D4强烈反应，与OS - 2反应较弱，表明存在不同类型的视觉色素。这些视杆细胞在形状上与主要的视杆细胞类型不同；它们更细、更短，可能与其他两栖动物的蓝敏（“绿”）视杆细胞相当。视锥细胞在形态上具有异质性：发现了双视锥细胞、大的单视锥细胞和小的单视锥细胞，并且大的单视锥细胞和双视锥细胞偶尔会出现重复。双视锥细胞和大的单视锥细胞（以及它们的重复变体）强烈结合单克隆抗体COS - 1，并且除了OS - 2外，未被所有其他单克隆抗体标记。小的单视锥细胞与COS - 1和“E”反应非常弱，被1D4和4B4弱标记，与OS - 2和11 - 7反应最强。小视锥细胞类型中这种独特的免疫细胞化学反应模式表明其视觉色素与非洲爪蟾视网膜中其他视锥细胞类型不同。本研究表明，在形态上不同（粗和细）的视杆细胞类型中存在两种不同的视蛋白，在异质性的视锥细胞群体中至少存在两种视锥色素。
