operon, genetic regulatory system found in bacteria and their viruses in which genes coding for functionally related proteins are clustered along the DNA. This feature allows protein synthesis to be controlled coordinately in response to the needs of the cell.

What organisms use operons?

Operons occur primarily in prokaryotes but also in some eukaryotes, including nematodes such as C. elegans and the fruit fly, Drosophila melanogaster. rRNA genes often exist in operons that have been found in a range of eukaryotes including chordates.

Why do bacteria use operons?

Bacterial Operons Are Coregulated Gene Clusters

In addition to being physically close in the genome, these genes are regulated such that they are all turned on or off together. Grouping related genes under a common control mechanism allows bacteria to rapidly adapt to changes in the environment.