Genome-wide expression analysis of the responses to nitrogen deprivation in the heterocyst-forming cyanobacterium Anabacna sp strain PCC 7120
Genome-wide expression analysis of the responses to nitrogen deprivation in the heterocyst-forming cyanobacterium Anabacna sp strain PCC 7120
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DOI：
10.1093/dnares/10.3.97
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发表时间：
2003-06-30
期刊：
影响因子：
4.1
通讯作者：
Sato, N
中科院分区：
文献类型：
--
作者：
Ehira, S;Ohmori, M;Sato, N
异形细胞是蓝藻的终末分化细胞，专门从事二氮固定。 Anabacna sp 中的异囊分化。菌株 PCC 7120 是通过培养基中组合硝基的缺失而触发的。尽管已经报道了在异形细胞分化过程中上调的各种基因，但迄今为止的大多数研究仅限于单个或少数基因。我们与鱼腥藻基因组计划的其他成员合作制备了微阵列。在这里，我们报告了鱼腥藻对氮剥夺反应的全基因组表达分析。许多未知的基因。以及先前已知的基因，被发现在不同时间点因氮缺乏而上调。发现了三个主要的基因表达谱：缺氮早期（1-3小时）瞬时表达的基因、后期（8小时）瞬时表达的基因以及异形囊形成时（24小时）表达的基因。我们还注意到，许多上调的基因在物理上聚集在一起，在染色体上形成“表达岛”。也就是说，包含许多基因的大的、连续的基因组区域以协调的方式上调。这表明基因表达的全局调控机制涉及染色体结构。这让人想起真核染色质重塑。讨论了这一全球监管的可能影响。
A heterocyst is a terminally differentiated cell of cyanobacteria which is specialized in dinitrogen fixation. Heterocyst differentiation in Anabacna sp. strain PCC 7120 is triggered by deprivation of combined nitro-en in the medium. Although various genes that are upregulated during heterocyst differentiation have been reported, most studies to date were limited to individual or a, small number of genes. We prepared microarrays in collaboration with other members of the Anabaena, Genome Project. Here we report on the genome-wide expression analysis of the responses to nitrogen deprivation in Anabaena. Many unidentified genes. as well as previously known genes, were found to be upregulated by nitrogen deprivation at various time points. Three main profiles of gene expression were found: genes expressed transiently at an early stage (1-3 hr) of nitrogen deprivation, genes expressed transiently at a later stage (8 hr), and genes expressed when heterocysts are formed (24 hr). We also noted that many of the upregulated genes were physically clustered to form 'expressed islands' on the chromosome. Namely, large, continuous genonlic regions containing many genes were upregulated in a coordinated manner. This suggests a mechanism of global regulation of gene expression that involves chromosomal structure. which is reminiscent of eukaryotic chromatin remodelling. The possible implications of this global regulation are discussed.