Genome Visualization by Isometric Projection Focused on Replication Origins and Termini, and Genome Instability

摘要

Intragenomic heterogeneity of GC content is generally more evident in higher eukaryotes than in prokaryotes and unicellular eukaryotes. Genomes of warm-vertebrates have long-range GC% mosaic structures that are related to chromosome bands. GC contentis considered a fundamental characteristic of each genome and of genomic regions. However, we believe that GC content is too simple a parameter to characterize the genome and specific genome regions. Each genomic sequence registered by the InternationalDNA Databank corresponds to one of the two DNA strands in a genome. Therefore, the G and A contents are not necessarily equal to the C and T contents, respectively. This tendency is more significant with respect to local sequence characteristics, and therefore, a method for effectively visualizing distribution of the four nucleotides in a three-dimensional space would be useful. We developed new techniques to visualize DNA sequence based on the fourth dimensional isometric projection and used this method to predict replication origins and termini in bacterial genomes.