| A lower intensity of mutagenesis can explain all observed revertants if each mutagenized cell has multiple copies of the lac operon. |
| If lactose enters the cell, it binds to the lac repressor and induces a change of shape in the repressor so that it can no longer bind to the DNA at the operon. |
| This can be achieved by changing the expression of a single sugar-specific repressor, causing a sugar-specific operon to become more or less inducible. |
| It has been noted that coexpressed genes are frequently situated as contiguous clusters within an operon. |
| Recently, the development of inducible expression systems has involved exploitation of the p-cym operon from Pseudomonas putida. |
| Although the operon model has proved a useful model of gene regulation in bacteria, different regulatory mechanisms are employed in eukaryotes. |
