Comparative genome analysis of the restriction-modification systems in cyanobacteria

Arthrospira or Spirulina is a cyanobacterium which is widely used as human health food and animal feed due to its high level of proteins, vitamins, pigments and unsaturated fatty acids. In addition, its extracts can enhance the immune system and improving health. Moreover, Arthrospira is the only cyanobacterium extensively grown outdoor on a large industrial scale. These characteristics led to the growing interest in Arthrospira as a cell factory for high value compounds production.

Currently, the genomes of 149 cyanobacterial strains are completely sequenced and the genomes sequencing of 257 cyanobacteria are in progress (as of October 27, 2014). The availability of genomic sequence data are extremely useful in searching for available RM genes including the novel genes based on the bioinformatics tools. In this study, the genes involved in RM systems in Arthrospira platensis C1 draft genome were analyzed, in comparison with the other 99 cyanobacterial genomes including Arthrospira platensis NIES-39 and A. maxima CS-328. The information of RM systems gained from the genome analysis will provide information about the RM systems for the genetic manipulation improvement of A. platensis C1 in the future.

Comparison of the RM systems in A. platensis C1 with other cyanobacteria

A total of 110,634 RM genes (as of July 2014) from REBASE database were downloaded ( and used for identification of RM genes from 100 cyanobacterial genomes via blastP from NCBI. All these RM genes were then compared to the other species using comparative genomic approaches (Figure 1). The result reveals information of RM genes in all 100 cyanobacterial strains using in this study, for RM classification in different cyanobacterial strains.

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