Real-time analyses of chloroplast and mitochondrial division and differences in the behavior of their dividing rings during contraction
Real-time analyses of chloroplast and mitochondrial division and differences in the behavior of their dividing rings during contraction
复制标题
实时分析叶绿体和线粒体的分裂及其分裂环在收缩过程中的行为差异
DOI：
10.1007/s004250050491
复制
发表时间：
1999
期刊：
影响因子：
4.3
通讯作者：
T. Kuroiwa
中科院分区：
文献类型：
--
作者：
S. Miyagishima;R. Itoh;K. Toda;H. Kuroiwa;T. Kuroiwa
抽象的。本文研究了紫腹青鱼CyanidioschyzonmerolaeDeLuca、Taddei和Varano的叶绿体和线粒体分裂的时间进程，以及叶绿体和线粒体分裂过程中质体分裂环（PD环）和线粒体分裂环（MD环）的形态变化。为了实现这一点，叶绿体和活细胞的细胞分裂在光学显微镜下连续录像，并在PD和MD环的形态变化进行了定量和三维的透射电子显微镜（TEM）分析。在光镜下，叶绿体和细胞的直径以均匀的速度减小，速度取决于温度。为了详细研究M期叶绿体膜的连续形态变化以及叶绿体和膜的分裂面的收缩机制，我们在透射电镜下观察了被认为促进收缩的PD和MD环，使用叶绿体直径作为时间的指标。三个PD环（外膜的细胞质表面上的外PD环，在膜间隙中的中间PD环，和内膜的基质表面上的内PD环）被清楚地观察到，但只能观察到外MD环。PD环在形成后不久就开始收缩，而MD环的收缩在形成后并不立即发生，而是延迟到PD环的收缩几乎完成。一旦MD环开始收缩，其周长的减小速率是PD环的4倍。随着外PD和MD环收缩，它们变厚并保持恒定的体积，而内PD环的厚度没有变化，其体积随着收缩以恒定的速率减小。在收缩早期，三个PD环的宽度从外到内环依次增加。随着收缩，它们的宽度以不同的速率变化，直到它们的宽度基本相同。在横截面上，MD环在靠近叶绿体的地方比在相反侧更宽，在收缩的早期阶段靠近核。到了后期，两边的宽度变得相等。在我们的观察中，微体沿着外MD环伸长，并在PD和MD环收缩期间接触外PD环。这些结果清楚地揭示了外，中，内PD环的收缩模式之间的差异，以及PD和MD环之间的差异。他们还揭示了三个PD环的协调加宽，并建议微体在PD和MD环的收缩中起作用。
Abstract. The time courses of chloroplast and mitochondrial division and the morphological changes in the plastid-dividing ring (PD ring) and mitochondrion-dividing ring (MD ring) during chloroplast and mitochondrial division were studied in Cyanidioschyzon merolae De Luca, Taddei and Varano. To accomplish this, chloroplast and cell division of living cells were continuously video-recorded under light microscopy, and the morphological changes in the PD and MD rings were analyzed quantitatively and three-dimensionally by transmission electron microscopy (TEM). Under the light microscope, the diameters of the chloroplast and the cell decreased at uniform velocities, the speed depending on the temperature. To study in detail the sequential morphological change of the mitochondrion in M phase and the contractile mechanism in the divisional planes of the chloroplast and the mitochondrion, we observed the PD and MD rings, which are believed to promote contraction, under TEM, using the diameter of the chloroplast as an index of the time. Three PD rings (an outer PD ring on the cytoplasmic face of the outer envelope, a middle PD ring in the intermembrane space, and an inner PD ring on the stromal face of the inner envelope) were clearly observed, but only the outer MD ring could be observed. The PD ring started to contract soon after it formed, while the contraction of the MD ring did not occur immediately after formation, but was delayed until the contraction of the PD ring was almost complete. Once the MD ring began to contract, the rate of decrease of its circumference was 4 times as high as that of the PD ring. As the outer PD and MD rings contracted, they grew thicker and maintained a constant volume, while the thickness of the inner PD ring did not change and its volume decreased at a constant rate with contraction. In the early stage of contraction, the widths of the three PD rings increased in order, from the outer to the inner ring. With contraction, their widths changed at different rates until they came to have much the same width. In cross-section, the MD ring was wider where it was next to the chloroplast than at the opposite side, adjacent to the nucleus in the early stage of contraction. By the late stage, the widths of the two sides became equal. In our observations, the microbody elongated along the outer MD ring and touched the outer PD ring during contraction of the PD and MD rings. These results clearly revealed differences between the mode of contraction of the outer, middle, and inner PD rings, and between the PD and the MD rings. They also revealed the coordinated widening of the three PD rings, and suggested that the microbody plays a role in the contraction of the PD and MD rings.
影响因子：
4
作者：
Kuroiwa, T
通讯作者：
Kuroiwa, T