Mycobacterium leprae
Since most bacteria that carry pseudogenes are either symbionts or obligate intracellular parasites, genome size eventually reduces. An extreme example is the genome of "Mycobacterium leprae", an obligate parasite and the causative agent of leprosy. It has been reported to have 1,133 pseudogenes which give rise to approximately 50% of its transcriptome. The effect of pseudogenes and genome reduction can be further seen when compared to "Mycobacterium marinum", a pathogen from the same family. "Mycobacteirum marinum" has a larger genome compared to "Mycobacterium leprae" because it can survive outside the host, therefore, the genome must contain the genes needed to do so.