Induction (birth)

Inducible gene is a type of gene that is not constantly active in a cell, but can be turned on or "induced" under certain conditions. This is in contrast to constitutive genes, which are continuously expressed. Inducible genes play a crucial role in the adaptive response of organisms to environmental changes.

Function

Inducible genes are typically involved in adaptive responses. They are not necessary for the basic function of the cell, but are required under specific conditions. For example, in bacteria, the lac operon is an inducible gene system that is activated in the presence of lactose. Similarly, in human cells, genes involved in the immune response, such as those encoding interferons, are inducible and are activated in response to viral infection.

Regulation

The expression of inducible genes is tightly regulated at the level of transcription. This is achieved through the action of transcription factors, proteins that bind to specific sequences in the DNA and either promote or inhibit the initiation of transcription. In many cases, the transcription factors themselves are regulated, either by changes in their activity or their abundance in the cell.

Examples

One well-studied example of an inducible gene is the lac operon in the bacterium Escherichia coli. This system is activated in the presence of lactose, which serves as both an inducer and a substrate for the enzymes encoded by the operon.

In humans, many genes involved in the immune response are inducible. For example, the genes encoding interferons are activated in response to viral infection. These proteins have antiviral activity and play a crucial role in the body's defense against viruses.

See also

• Gene expression
• Transcription (genetics)
• Operon
• Regulation of gene expression