Wang Wen, Chen Jianxiu, Du Kaihe, Xu Zaikuan
Department of Biological Science and Technology, Nanjing University, Nanjing 210093, PR China.
Res Microbiol. 2004 Oct;155(8):630-5. doi: 10.1016/j.resmic.2004.04.010.
The structure of spiroplasmas in the Chinese mitten crab associated with tremor disease was studied by transmission electron microscopy techniques, including both negative staining and ultrasectioning. A spiral structure, which is a typical form of spiroplasmas, could be detected and the observations showed for the first time the presence of spiroplasmas in the cells of the crab. Propagation of spiroplasmas within the cells presented various forms that could be sorted into three morphological types: rounded, regular helical, and pleiomorphic or intermediate forms. The spiroplasmas appeared as round bodies during the fallow stage of development or under poor conditions. They showed various shapes such as helices, saccate, branched, tadpole-like and tortoise-like structures while growing, and became long and congregated in late stages of development. When spiroplasmas were isolated from chicken eggs and cultured in M1D medium they appeared to undergo similar morphological changes to those in the crab. The spiroplasmas contained chromatin filaments and peripheral ribosome-like granules and were delimited by distinct unitary membranes. Average diameters were calculated at 0.1 to 0.35 microm for rounded forms and 0.1-0.2 microm for helical or long forms, and they varied in length from 3-12 microm.
利用包括负染色和超薄切片在内的透射电子显微镜技术，对与颤抖病相关的中华绒螯蟹体内的螺原体结构进行了研究。可以检测到螺旋结构，这是螺原体的典型形态，这些观察首次表明在蟹的细胞中存在螺原体。螺原体在细胞内的增殖呈现出多种形态，可分为三种形态类型：圆形、规则螺旋形以及多形或中间形态。在发育的休止期或条件不佳时，螺原体呈现为圆形体。它们在生长过程中呈现出各种形状，如螺旋形、囊状、分支状、蝌蚪状和龟状结构，并在发育后期变长并聚集。当从鸡蛋中分离出螺原体并在M1D培养基中培养时，它们似乎经历了与蟹体内相似的形态变化。螺原体含有染色质细丝和外周核糖体样颗粒，并由明显的单位膜界定。圆形形态的平均直径计算为0.1至0.35微米，螺旋形或长形的平均直径为0.1 - 0.2微米，其长度在3 - 12微米之间变化。
