斜带石斑鱼胸腺的显微和超微结构  

Microstructure and ultrastructure of the thymus of orange-spotted groupers Epinephelus coioides

作　　者：吴金英[1] 林浩然[1] 

机构地区：[1]中山大学生命科学学院水生经济动物研究所暨广东省水生经济动物良种繁育重点实验室,广州510275

出　　处：《动物学报》2008年第2期342-355,共14页ACTA ZOOLOGICA SINICA

基　　金：国家973项目(No.2006CB101805);国家海洋863项目(No.2001AA621010);广东省自然科学基金项目(No.05003313)资助~~

摘　　要：本文通过解剖及组织切片技术、光学显微镜、透射和扫描电子显微镜技术,对斜带石斑鱼(Epinephelus coioides)胸腺器官组织进行了观察研究。结果表明:斜带石斑鱼胸腺实质主要由胸腺细胞(淋巴细胞)和网状上皮细胞构成。鱼体从Ⅰ龄之后,其胸腺发生明显的变化,与幼鱼有所不同,主要是胸腺可明显区分为三个区域:胸腺外皮质区、内皮质区和髓质区。外皮质区主要由网状上皮细胞、黏液细胞、成纤维细胞和少量淋巴细胞构成,细胞排列疏松;内皮质区主要由密集的淋巴细胞和网状上皮细胞组成,以含有大量的淋巴细胞为特征;髓质区主要由淋巴细胞和较多的网状上皮细胞构成,总体特征是淋巴细胞数量比内皮质区的少,且细胞排列较疏松。外皮质区、内皮质区相当于高等脊椎动物的皮质;髓质区相当于高等脊椎动物的髓质。髓质区之下有结缔组织,在Ⅱ龄以上的成体出现胸腺小体(Hassall's corpuscles)或类似胸腺小体的结构,而且随着年龄的增加,胸腺外皮质区增厚,结缔组织增加,还表现在内皮质区和髓质区组织逐渐萎缩变薄,胸腺的细胞组成类型和淋巴细胞数量上有所变化等等。这些现象在Ⅱ龄鱼开始出现,即胸腺呈现退化迹象,在Ⅲ龄以上鱼体呈现明显的退化和萎缩。胸腺表面扫描电镜结果表明:其上皮细胞表面具有微嵴以及由微嵴组成的指纹状结构,有一些微孔分布。透射和断面扫描电镜的结果进一步表明:胸腺组织内的细胞成分复杂,除了淋巴细胞和网状上皮细胞外,还具有巨噬细胞、肥大细胞、肌样细胞、浆细胞、指状镶嵌细胞和纤维细胞等。Morphological and histological structure of the thymus in Epinephelus coioides was investigated using anatomical and histological techniques, the light microscope, and scanning electron and transmission electron microscopes. The thymus was located on the superior dorsolateral comer of the gill cover close to the opercular cavity, and a paired organ lay superficially in close association with the epithelial lining of the branchial cavity. Results showed that the thymus was essentially composed of thymocytes （lymphocytes） and reticuloepithelial cells. Unlike the thymus of young fish, the thymus of fish one-year-old or older displayed three regions： the outer cortex, inner cortex and medulla. The outer cortex consisted mainly of loosely distributed reticuloepithelial cells, mucous cells, fibroblasts and relatively few lymphocytes compared to the other regions. The inner cortex consisted mainly of reticuloepithelial cells and tightly packed lymphocytes, this region of the thymus contains a larger number of lymphocytes than the other regions. The medulla also consisted mainly of lymphocytes and reticulocpithelial cells. The medulla contained more reticuloepithelial cells and fewer lymphocytes, with a looser distribution of these lymphocytes than was found in the inner cortex ; the cells of this region were loosely distributed. The thymic outer cortex and inner cortical regions of E. coioides were similar to the thymic cortex zone of the higher vertebrates. The thymic medulla region, with the presence of connective tissue, was similar to the corresponding region of the thymus in higher vertebrates. Hassall＇s body-like structures/Hassall＇ s corpuscles were seen in the thymus of the fish aged two-years-old or older. With increasing age, the thymic outer cortex became thicker, and the connective tissue in the thymus increased, whereas the thymic inner cortex and medulla gradually became smaller and thinner. In addition, the cells types changed and the numbers of lymphocytes differed in the thymic inner cortex an

关 键 词：斜带石斑鱼 胸腺 显微结构 超微结构 

分 类 号：Q954[生物学—动物学]