摘要
应用透射电子显微镜观察了文昌鱼 (BranchiostomabelcheritsingtauenseTchangetKoo)鳃骨条的结构。发现其鳃条骨条横切面的外部 ,有时可见两个相连的细胞密集区 ,细胞排列紧密 ,核质比大。除此之外的基质区 ,由平均直径 2 8 3nm的粗纤维构成。在该区域的外围 ,粗纤维与边缘平行排列成薄层。在内部 ,粗纤维交错排列。而鳃条骨条横切面内部及整个舌条骨条则是由平均直径分别为 13 8nm和 13 9nm的细纤维构成的。细纤维排列规则 ,与鳃骨条的长轴平行。且彼此间由横向的细丝状交联连接成为直角的方格结构。两种纤维在形态上与胶原纤维不同。显示文昌鱼的鳃骨条是一种特殊的、非胶原为基质的支持组织。这使得继无颌类七鳃鳗和盲鳗中已发现的至少 4种非胶原为基质的软骨家族又增添了新的成员 ,且文昌鱼鳃骨条与七鳃鳗和盲鳗的非胶原为基质的软骨结构都不相同 ,提示文昌鱼与无颌类可能有着长期独立的进化历史。
The observation on the ultra-structure of the gill skeleton in the lancelet by TEM (Transmission Electron Microscopy) occasionally reveals two areas of crowded cells with a higher ratio of nucleus vs. cytoplasm in the outside of the gill bar skeletal rods. The surrounding matrix is composed of thick fibrils with an average diameter of 28.3 nm, which are parallel each other to form a thin layer in the outer part, but they crisscross to form a complex structure in the inner part. The tongue bar skeletal rod and the inside of the gill bar skeletal rod are composed of thin fibrils with average diameter of 13.9 nm and 13.8 nm respectively, which are regularly arranged side by side, paralleling to the long-axis of the gill skeleton. The thin fibrils are interconnected by short cross-linkages, forming a lattice structure with a rectangular arrangement. Both types of fibrils are different from collagenous filament in terms of morphology, and indicate that the gill skeleton in the lancelet is an unusual, non-collageous based supporting tissue. Now a new member joins the non-collagenous cartilage family, which has been found in agnathans (lampreys and hagfishes). And the structure of lancelet's gill skeleton is different from both lamprey′s and hagfish′s, which implies lancelet may have a long independent history of evolution with Agnatha.
出处
《海洋水产研究》
CSCD
2004年第5期12-18,共7页
Marine Fisheries Research
基金
国家自然科学基金项目 (30 0 70 1 1 0 1 )资助
关键词
文昌鱼
鳃骨条
基质纤维
超微结构
Lancelet (Branchiostoma belcheri tsingtauense) Gill skeleton Matrix fibril Ultra-structure
