CONFIGURATION PATTERN OF CT-NUCLEOIDS IN DIATOMS

用dapi染色的硅藻（16属50种）对叶绿体-类核（ct-类核）结构进行了检测。除几种Pinnularia和Nitzschia外，其余种均为环状结构，分别观察到分散的dapi荧光球和短串的dapi荧光。由于dapi荧光球经DNA酶处理后消失，证实其含有DNA。通过共聚焦激光显微镜和Technovit 7100包埋细胞切片的观察，证实这些小球体位于叶绿体中。在透射电镜观察中，这些球对应于类囊体堆积的离散区域。这些区域未见膜性结构。叶绿体被分离出来，然后这些球也被分离出来。小球的大小与环状类核中每个小珠的大小相似。利用蛋白酶K处理，这些小球被裂解，然后DNA被扩散。更多的离子和实验证明，分散在叶绿体中的小球体是DNA和蛋白质复合物的类核。在Pinnularia中，有11种具有环状ct样核，9种具有散点型ct样核和环状ct样核，1种仅具有散点型ct样核。分散型的种类仅限于p.a sect的硅藻。刺草和刺草组Divergentissima。丙-胭脂红染色法观察到乙字形尼氏虫叶绿体中散布着小的矩形类pyrenoids。透射电镜下，它们呈透镜状，这是硅藻的典型特征。利用间接免疫荧光显微镜和免疫金电镜检测了Rubisco在该结构中的特异性定位。虽然在该物种中未观察到环状类核，但在类核蛋白两侧观察到线性dapi荧光，它们似乎是ct-类核。硅藻中ct-类核的构型与硅藻小体一样多样，似乎反映了它们的系统分类学。少

Configurations of chloroplast-nucleoids (ct-nucleoid) were examined with DAPI-stained diatoms (16 genera, 50 species). The configuration was ring-type in all species except for several Pinnularia and Nitzschia species, in which scattered DAPI-fluorescent globules and short strings of DAPI-fluorescence were observed respectively. As DAPI-fluorescent globules in Pinnularia disappeared by DNase treatment, they were confirmed to contain DNA.These globules were confirmed to be located in the chloroplast by confocal laser microscopy and observations of the sections of the cells embedded in Technovit 7100. These globules corresponded to the discrete areas of thylakoids stack in TEM observation. No membranous structure was detected in these areas. The chloroplasts were isolated and then these globules also isolated. The size of globules were similar to that of each beads in ring-type nucleoid. Employing proteinase K treatment, these globules were lysed and then DNA was diffused. These observat … More ions and experiments prove that the globules scattered throughout the chloroplast are the nucleoids to be a complex of DNA and protein. In Pinnularia, 11 species have the ring-type ct-nucleoid and 9 species have the scattered-type nucleoid as well as the ring-type and 1 species has only the scattered-type. Species with the scattered-type are limited in diatoms of P.sect. Pinnularia and P.sect. Divergentissima. In Nitzschia sigmoidea, we observed that small rectangular pyrenoids were scattered throughout the chloroplasts by propion-carmine staining method. In TEM section, they were lens shape, which was typical in diatoms. Specific localization of Rubisco was detected in this structure using indirect immuno-fluorescence microscopy and electron microscopy with immuno-gold. Although the ring-type nucleoid was not observed in this species, linear DAPI-fluorescence was observed along both sides of the pyrenoids and they seem to be the ct-nucleoids. The configurations of ct-nucleoids in diatoms are diversified as in diatom frustules, and seem to reflect their systematics. Less