Phase Variation - Gene Conversion

Gene Conversion

Gene conversion is another example of a type of phase variation. Type IV pili of Neisseria gonorrhea are controlled in this way. There are several copies of the gene coding for these pili (the Pil gene) but only one is expressed at any given time. This is referred to as the PilE gene. The silent versions of this gene, PilS, can use homolygous recombination to combine with parts of the PilE gene and thuse creat a different phenotype. This allows for up to 10,000,000 different phenotypes of the pili.