The copy number of chloroplast gene minicircles changes dramatically with growth phase in the dinoflagellate Amphidinium operculatum
The copy number of chloroplast gene minicircles changes dramatically with growth phase in the dinoflagellate Amphidinium operculatum
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DOI：
10.1016/j.protis.2006.08.003
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发表时间：
2007-01-01
期刊：
影响因子：
2.5
通讯作者：
Howe, Christopher J.
中科院分区：
文献类型：
--
作者：
Koumandou, V. L.;Howe, Christopher J.
藻类和植物的叶绿体基因组通常包含100-200 kb的环状DNA分子，其含有类似于120个基因，并且每个叶绿体以50-100个拷贝存在。然而，在多甲藻甲藻，一个生态上重要的单细胞藻类，叶绿体基因组被分割成质粒样的“小环”，每个2-3 kb。此外，甲藻的叶绿体基因含量显著降低。在甲藻小环上只发现了14个基因，最近的EST研究证据表明，大多数通常位于其他藻类和植物叶绿体中的基因位于细胞核中。在这项研究中，Southern印迹分析被用来估计每个细胞的拷贝数的各种小环在不同的生长阶段的甲藻藻operculatum。发现小环拷贝数在指数生长阶段期间较低，但在生长后期期间增加，类似于在其他植物和藻类中看到的情况。根据这些发现的控制小环复制进行了讨论。(c)2006年Elsevier GmbH。All rights reserved.
The chloroplast genome of algae and plants typically comprises a circular DNA molecule of 100-200 kb, which harbours similar to 120 genes, and is present in 50-100 copies per chloroplast. However, in peridinin dinoflagellates, an ecologically important group of unicellular algae, the chloroplast genome is fragmented into plasmid-like `minicircles', each of 2-3 kb. Furthermore, the chloroplast gene content of dinoflagellates is dramatically reduced. Only 14 genes have been found on dinoflagellate minicircles, and recent evidence from EST studies suggests that most of the genes typically located in the chloroplast in other algae and plants are located in the nucleus. In this study, Southern blot analysis was used to estimate the copy number per cell of a variety of minicircles during different growth stages in the dinoflagellate Amphidinium operculatum. It was found that minicircle copy number is low during the exponential growth stage but increases during the later growth phase to resemble the situation seen in other plants and algae. The control of minicircle replication is discussed in the light of these findings. (c) 2006 Elsevier GmbH. All rights reserved.