BEHAVIOR OF CHLOROPLAST NUCLEOIDS DURING THE CELL-CYCLE OF CHLAMYDOMONAS-REINHARDTII (CHLOROPHYTA) IN SYNCHRONIZED CULTURE
BEHAVIOR OF CHLOROPLAST NUCLEOIDS DURING THE CELL-CYCLE OF CHLAMYDOMONAS-REINHARDTII (CHLOROPHYTA) IN SYNCHRONIZED CULTURE
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DOI：
10.1111/j.0022-3646.1990.00317.x
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发表时间：
1990-06-01
影响因子：
2.9
通讯作者：
HASE, E
中科院分区：
文献类型：
--
作者：
EHARA, T;OGASAWARA, Y;HASE, E
在12:12 h的光照：黑暗条件下，莱茵衣单胞菌细胞同步生长。它们的大小在光照期增大，而细胞核分裂、叶绿体分裂和细胞质分裂发生在黑暗期。游动孢子在黑暗时期结束时被释放出来。用0.1% （w/v）戊二醛固定后，用DNA荧光染料4”，6-二氨基-2-苯基吲哚（DAPI）染色，在荧光显微镜下观察叶绿体类核的轮廓和分布变化。在光照初期（0 h），叶绿体中约有10个颗粒状的类核分散。在4小时内，类核聚集在类芘周围，形成致密的轮廓。类核周围致密的共核聚集体的形成在光期出现了两次最高频率。在光照期结束时，类核转变成线的形式，细原纤维在叶绿体中相互连接。最初，丝状的类核只发出微弱的荧光。丝状结构的部分荧光在6小时后变得更亮；这些类核在叶绿体分裂过程中分裂成子叶绿体。叶绿体分裂后不久，这些线状的类核转变成大约20个颗粒状，在游动孢子中，这些颗粒状体在脱离母细胞之前，逐渐结合成大约10个更大的颗粒体。用高浓度戊二醛固定细胞或用蛋白酶处理细胞可显著改变dapi染色的类核结构。讨论了叶绿体类核的不同形态与它们的蛋白质组分结构变化的关系。
Cells of Chlamydomonas reinhardtii Dangeard were synchronized under a 12:12 h light: dark regimen. They increased in size during the light period, while nuclear division, chloroplast division and cytokinesis occurred during the dark period. Zoospores were liberated toward the end of the dark period. Changes in profile and distribution of chloroplast nucleoids were followed with a fluorescence microscope after fixation with 0.1% (w/v) glutaraldehyde followed by staining with 4'',6-diamidino-2-phenylindole (DAPI), a DNA fluorochrome. About ten granular nucleoids were dispersed in the chloroplast at the beginning of the light period (0 h). Withing 4 h the nucleoids aggregated around the pyrenoid giving a compact profile. The formation of the compact aggregate of co-nucleoids around the pyrenoid occurred with maximal frequency twice during the light period. Toward the end of the light period the nucleoids were transformed into the form of threads interconnected with fine fibrils spreading throughout the chloroplast. Initially the thread-like nucleoids fluoresced only faintly. The fluorescence of some parts of the thread-like form became brighter over a period of 6 h; these nucleoids were divided into daughter chloroplasts during chloroplast division. Soon after chloroplast division, these thread-like nucleoids were transformed into about 20 granular forms, which were gradually combined to form about ten larger granular bodies in zoospores immediately prior to liberation from mother cells. Fixation of cells with glutaraldehyde at high concentrations or treatment of cells with protease significantly modified the profiles of DAPI-stained nucleoids. The different morphologies of chloroplast nucleoids are discussed in relation to changes in configuration of their protein components.