The number of potential targets in the NCBI Nucleotide Collection and in the <i>Porphyromonas</i> genomes, and dissection of the latter group by focusing on the locational relationships between the CRISPR spacer and its potential targets.

<p>(A) The number of potential targets of the <i>Porphyromonas</i> CRISPR arrays in the NCBI Nucleotide Collection and in the <i>Porphyromonas</i> genomes are shown in the left and right bar charts, respectively. In each chart, the numbers are presented, based on the number of mismatches. The numbers for the <i>Porphyromonas</i> genomes are excluded from the chart for the NCBI Nucleotide Collection. (B) The Venn diagram shows the relationships among spacers having intraspecies or interspecies targets and endogenous or exogenous targets. Two circles for spacers with endogenous and exogenous targets are overlapped on the left side to form one large population of spacers with intraspecies targets. This circle is overlapped with one circle on the right for spacers with interspecies targets. For instance, the number 33 indicates spacers with both endogenous and exogenous targets but without any interspecies targets. (C) The relationships between CRISPR spacers and their potential targets in <i>Porphyromonas</i> species. The left side presents the name of species with CRISPR arrays, and the lower axis shows species with potential targets of the CRISPR spacers in the genomes of the species on the left. The presence or absence of potential targets is indicated by blue or gray, respectively, and those that are targeted by CRISPR spacers of the same species are indicated by red.