Origin of Eukaryotic Algae from a view point of chloroplast nucleoids in Cyanidium.

从原核生物到真核生物的进化，一直是内共生学说和直接亲缘学说争论的焦点。我们最近的实验可以从细胞结构的真核程度的角度为这一讨论提供材料。其中，Cyaniaium caldarium RK-1具有核、叶绿体和叶绿体，是真核生物中分类地位最低的重要生物之一。本研究采用DAPI染色法和荧光显微镜技术，测定了核和叶绿体类核DNA含量。用荧光显微镜测定了蓝藻类核的面积与单细胞大小的比值，结果表明，蓝藻类核的面积与单细胞大小的比值在绿色藻中有极高的水平。而用光子计数器测定的单细胞DNA含量为其它微藻的平均值。光子数计算 关于我们 用VIM系统测定的DNA含量几乎与DNA含量成正比。用这种方法计数的蓝藻细胞核中的DNA比其他藻类细胞的DNA含量少得多。细胞器类核/核的DNA比值可作为真核生物进化程度的一个指标。RK-1的平均值为0.378，包括0.198（年轻细胞）至0.454（老化细胞）。另外，M-8菌株在光照生长的幼细胞中的值为1.247，在黑暗生长的幼细胞中的值为0.308。RK-1菌株的叶绿体类核呈杆状（CN型），与蓝藻类相似; M-8菌株的叶绿体类核呈环状（CL型），与褐藻类或硅藻类相似。这些结果表明，这两个菌株的Cyanidium caldarium之间有相当大的差异，Cyanidium RK-1型可能是唯一的微藻，因为它具有显着的奇数碳编号的正链烷酸的量。少

The evolution from Prokaryote to Eukaryote has been discussed a long time between Endosymbiotic Theory and Direct Filiation Theory. The present task on our recent trials could offered a material for this discussion from a view point of eukaryotic degree of cell structure. Among them, Cyaniaium caldarium RK-1 which possesses each one of nucleus, chloroplast, and mitochondrion, is one of the most important organisms as is situated in the lowest taxonomic position of Eukaryote. In the present study we used DAPI staining and Fluorescence Microscopy including VIM-system, and determined the DNA contents in the nucleus and chloroplast nucleoids. These data were compared with other Prokaryotic and Eukaryotic organisms.The ratios of nucleoids area to single cell size determined by Fluorescence Microscopy presented exceeding high levels in Blue Green Algae. But the DNA contents per single cell determined by a photon counter presented the average values among other mocro-algae. Photon numbers cou … More nted with VIM-system seem almost proportional to DNA contents exactly. DNA in the nucleus of Cyanidium cells counted by this method indicate considerable small amounts than those of other algal cells. But the DNA contents per single cell presented about an average value according to their small cell sizes.DNA ratio of organelle nucleoid to nucleus significantly suggests to be an indicator of Eukaryotic degree in evolution. RK-1 has an average value of 0.378 which includes from 0.198(young cells) to 0.454(aged cells). Otherwise M-8 strain presented a value of 1.247 in light grown young cells, and 0.308 in dark grown young cells, respectively. We presented the result that RK-1 strain resembles to Cyanophyta type because of its rod shaped chloroplast nucleoid(CN-type), on the other hand M-8 strain resembles to Phaeophyt or Bacillariophyta bacause of its ring shaped chloroplast nucleoid(CL-type).Gaschromatographic analyses of hydrocarbons and fatty acids in two strains of Cyanidium caldarium were carried out. These results indicate a considerable difference between the two strains of Cyanidium caldarium,and Cyanidium RK-1 type may be unique among microalgae because it has a significant amount of odd-carbon numbered n-alkanoic acids. Less