Definition

1. Noun:
   • A gene that prevents the expression of another gene: A repressor gene is a specific type of regulatory gene. Its primary function is to produce a repressor protein. This protein binds to a specific operator region of DNA, thereby blocking the process of transcription for another gene or set of genes (operon). This mechanism is a fundamental part of gene regulation in cells, allowing them to control which proteins are produced and in what quantities.

Usage Examples

• Noun:
  • The lac repressor gene in E. coli controls the metabolism of lactose.
  • Mutations in a repressor gene can lead to the constant production of enzymes, wasting cellular resources.
  • Scientists studied how the repressor gene turns off the expression of viral DNA.

Advanced Usage

• "Repressor gene mutation": A change in the DNA sequence of a repressor gene. This can result in a non-functional repressor protein, leading to constitutive (constant) expression of the genes it normally controls.
  • The experiment demonstrated that a repressor gene mutation caused the bacteria to produce the enzyme continuously.

Variants and Related Words

• Repressor (n): The protein product synthesized by a repressor gene, which performs the actual function of binding to DNA to inhibit transcription.
  • The repressor binds to the operator site.
• Repress (v): The general action of inhibiting or suppressing. In genetics, it specifically refers to the inhibition of gene transcription.
• Repressible operon: An operon (a cluster of genes controlled together) whose transcription is typically on but can be turned off by a repressor protein.

Synonyms

• Regulatory gene: A broader term for any gene involved in controlling the expression of other genes. A repressor gene is a specific type of regulatory gene.
• Inhibitor gene: A less common but descriptive synonym emphasizing its inhibitory function.

Related Phrases and Concepts

• Gene regulation: The overall process by which cells control gene expression, of which repression is a key mechanism.
• Operator: The specific DNA sequence where the repressor protein binds to block transcription.
• Inducer: A molecule that can inactivate a repressor protein, thereby turning gene expression back on.

Noun

1. gene that prevents a nonallele from being transcribed