- The synthesis of an RNA copy from a sequence of DNA (a gene); the first step in gene expression.
Definition from: Human Genome Project Information
at the U.S. Department of Energy
- Transcription is the process of making an RNA copy of a gene sequence. This copy, called a messenger RNA (mRNA) molecule, leaves the cell nucleus and enters the cytoplasm, where it directs the synthesis of the protein, which it encodes.
Definition from: Talking Glossary of Genetic Terms from the National Human Genome Research Institute
Related discussion in the Handbook
See also Understanding Medical Terminology.