A systematic forward genetic analysis identified components of the Chlamydomonas circadian system
A systematic forward genetic analysis identified components of the Chlamydomonas circadian system
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DOI：
10.1101/gad.1650408
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发表时间：
2008-04-01
影响因子：
10.5
通讯作者：
Ishiura, Masahiro
中科院分区：
文献类型：
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作者：
Matsuo, Takuya;Okamoto, Kazuhisa;Ishiura, Masahiro
生物钟的分子基础已经在动物、真菌、细菌和植物中进行了研究，但还没有在真核藻类中进行过研究。为了建立一个新的生物钟的分子分析模型，在这里，我们确定了大量的真核单细胞衣藻昼夜节律系统的组成部分，通过系统的正向遗传方法。我们分离出105个插入突变体，表现出缺陷的周期，相位角，和/或振幅的昼夜节律的生物发光来自荧光素酶报告基因在他们的叶绿体基因组。同时测量生物发光和生长速率的昼夜节律发现，这些突变体中的一些有缺陷的生物钟本身，而一个突变体有一个缺陷的叶绿体生物发光节律的特定过程。我们确定了30个基因（或基因位点），将负责37个突变体的节奏缺陷。对这些基因的分类揭示了叶绿体节律性的调控涉及多种生物学过程。在生物钟中起关键作用的六个基因的氨基酸序列揭示了衣原体时钟的特征，这些特征既有部分植物样成分，也有原始成分。
The molecular bases of circadian clocks have been studied in animals, fungi, bacteria, and plants, but not in eukaryotic algae. To establish a new model for molecular analysis of the circadian clock, here we identified a large number of components of the circadian system in the eukaryotic unicellular alga Chlamydomonas reinhardtii by a systematic forward genetic approach. We isolated 105 insertional mutants that exhibited defects in period, phase angle, and/or amplitude of circadian rhythms in bioluminescence derived from a luciferase reporter gene in their chloroplast genome. Simultaneous measurement of circadian rhythms in bioluminescence and growth rate revealed that some of these mutants had defects in the circadian clock itself, whereas one mutant had a defect in a specific process for the chloroplast bioluminescence rhythm. We identified 30 genes (or gene loci) that would be responsible for rhythm defects in 37 mutants. Classification of these genes revealed that various biological processes are involved in regulation of the chloroplast rhythmicity. Amino acid sequences of six genes that would have crucial roles in the circadian clock revealed features of the Chlamydomonas clock that have both partially plant-like and original components.