Ultrastructural Study on the Mechanism of Photoreception in Chromatophores of Poikilothermal Vertebrates

非洲爪蟾蝌蚪和青鳉蝌蚪的光敏色素细胞表面有泡状突起。突起通常含有层状结构，显示出与感觉感受器的惊人相似性，但没有基底体或相关结构。它并不普遍存在于感光色素细胞中：它不存在于南极鱼的黄色素细胞中，也不存在于刚毛冠藻的色素细胞中。青鳉dm和dm-2突变体的不动色素细胞和珠被中的非色素细胞偶尔具有类似的突起。利用抗牛视紫红质的单克隆抗体研究了色素细胞中视觉启动子的定位。免疫荧光显微镜观察组织切片和分离的细胞，使用链霉亲和素-生物素系统。在爪蟾的色素上皮细胞中观察到强烈的免疫反应，而在爪蟾的光敏尾部黑色素细胞中没有免疫反应。 关于我们 分段材料。一个弱的阳性反应被发现在分离的细胞，但不光敏黑色素细胞的爪蟾和光敏色素细胞的青鳉被标记。以胶体金为探针进行免疫电镜观察。在预包埋方法中，在标记之前对组织进行透化。结构的保留是可以容忍的，但标签是穷人。包埋后在免疫标记方面得到了更好的结果，尽管结构的保留不足以鉴定细胞组分。包埋前爪蟾光敏黑色素细胞呈阴性反应，包埋后的样品在细胞质中有反应产物沉积。进一步改进的方法，以获得更好的保存的精细结构和抗原性正在调查中。视紫红质样抗原的存在，在SDS提取爪蟾尾鳍已检查通过Western印迹。目前正在审查有关组分的抗原性。少

Photosensitive chromatophores of Xenopus laevis tadpoles and those of the medaka Oryzias latipes have vesicular protrusions on the surface of the cell. The protrusion often contains lamellar structure, showing striking similarity to sensory receptors, but does not have basal bodies or related structures. It is not ubiquitous among photosensitive chromatophores: It does not occur in xanthophores of an Antarctic fish nor in chromatophores of Diadems setosum. Immotile chromatophores of the mutants of medaka dm and dm-2 and non-pigment cells in the integument occasionally possess similar protrusions.Localization of visual prigment in chromatophores was examined by the use of a monoclonal antibody raised against bovine rhodopsin. Immunofluorescence microscopy was carried out on tissue sections and isolated cells using streptavidin-biotin system. A strong immunoreaction was observed in pigment epitheial cells of Xenopus while photosensitive tail melanophores exhibited no immunoreaction in se … More ctioned material. A weak positive reaction was found in isolated cells, but photoinsensitive melanophores of Xenopus and photosensitive chromatophores of the medaka were not labeled. Immunoelectron microscopy was performed using colloidal gold as a probe. In pre-embedding method, tissues were permeabilized before labeling. Preservation of structure was tolerable but labeling was poor. Post-embedding gave better result in regard to the immunolabeling though preservation of the structure was not sufficient to identify cellular components. Photosensitive melanophores of Xenopus gave negative result by preembedding while post embedded samples showed some deposition of the reaction product in the cytoplasm. Further improvement of the method to get better preservation of the fine structure and antigenicity is under investigation.The presence of rhodopsin-like antigen in SDS extract of Xenopus tail fin has been examined by Western blotting. Antigenicity of the fractions in question is now in review. Less