Fig. 5.

Type II CRISPR systems appear to be more prevalent in host-associated microbes. a The cas targeting genes associated with type I, type II, and type III systems (cas3, cas9, and cas10, respectively) mapped onto the PCA in Fig. S2. Organisms without any targeting genes were omitted from the plot for readability. Recall from Table 1 that PC1 roughly corresponds to a spectrum running from host-associated to free-living microbes. b A variable importance plot from an RF model of cas9 incidence. Observe that keywords related to a host-associated lifestyle appear many times