Phase variable DNA repeats in influence transcription, translation, and protein sequence variation.

There are many types of repeated DNA sequences in the genomes of the species of the genus , from homopolymeric tracts to tandem repeats of hundreds of bases. Some of these have roles in the phase-variable expression of genes. When a repeat mediates phase variation, reversible switching between tract lengths occurs, which in the species of the genus most often causes the gene to switch between on and off states through frame shifting of the open reading frame.

Inversion of Correia repeat enclosed elements in .

is capable of causing gonorrhoea and more complex diseases in the human host. Within the gonococcal genome are over 100 copies of the insertion sequence-like Correia repeat enclosed element (CREE), which has been predicted to be mobile within the neisserial genomes. Although there is evidence of ancestral movement of these elements, no previous study has provided evidence for current mobilization.