Mycobacterium leprae
Pseudogenes are found in bacteria. Most are found in bacteria that are not free-living; that is, they are either symbionts or obligate intracellular parasites. Thus, they do not require many genes that are needed by free-living bacteria, such as gene associated with metabolism and DNA repair. However, there is not an order to which functional genes are lost first. For example, the oldest pseudogenes in "Mycobacterium leprae" are in RNA polymerases and the biosynthesis of secondary metabolites while the oldest ones in "Shigella flexneri" and "Shigella typhi" are in DNA replication, recombination, and repair.