Insight into Microevolution of Yersinia pestis by Clustered Regularly Interspaced Short Palindromic Repeats
Figure 5
Evolutionary models of bv. microtus Cc3, Cc2 and Cc1 isolates.
A: A process from Cc3, through an ancestor of Cc2, to Cc1 with the loss of a series of spacers. B: The model proposes that Cc3 evolved to Cc1 by losing c2, c3 and b10, then to ancestor of Cc2 by acquiring c2 and b10. C: The model proposes that ancestor of Cc2 and Cc1 had no direct relation, but were formed separately by losing different spacers of Cc3.