We provide here an overview of our present understanding of the distribution of different insertion sequences (ISs) within bacterial genomes (both chromosomes and plasmids). This is at present fragmentary and a significant effort is needed in the analysis of the increasing number of genomes whose sequence has been determined. We also consider some of the properties of ISs which are important in their role of assembling, reassorting, and transmitting groups of genes.
Mahillon, J., Léonard, C., & Chandler, M. (1999). IS elements as constituents of bacterial genomes. Research in Microbiology, 150(9-10), 675-687. https://doi.org/10.1016/S0923-2508(99)00124-2 (Original work published 1999)