Fig 2. Schematic comparison of the trailer end of the arrays of spacers in Acinetobacter baumannii AYE and A. baumannii ab299505.

The region carrying spacers Ab-1 to Ab-4 in A. baumannii AYE was missing in A. baumannii ab299505, most likely due to an internal deletion caused by a recombination event between the two direct repeats (highlighted by a black frame) surrounding the deleted region. This created a unique direct repeat (highlighted by a black frame and vertical lines) characterized by a novel mosaic sequence derived from the recombined direct repeats. Sequence of the direct repeats involved in the recombination was presented in adjacent black boxes.