Life sciences · Reference
What is transcription?
Transcription is the first step in expressing a gene: the process by which the DNA sequence of a gene is copied into a complementary strand of RNA by the enzyme RNA polymerase.
Copying DNA into RNA
During transcription, the DNA double helix is opened at the gene to be expressed, and the enzyme RNA polymerase reads one strand as a template. It assembles a complementary strand of RNA, matching each DNA base with an RNA base (with uracil pairing to adenine in place of thymine). The result is a single-stranded RNA copy of the gene. Transcription is conventionally divided into three phases: initiation, elongation, and termination.
Promoters and control
Transcription begins at a regulatory region called a promoter, which marks where RNA polymerase should start and helps determine how often a gene is transcribed.
Additional regulatory sequences and proteins can increase or decrease transcription, allowing cells to control which genes are copied and how much RNA is made. This regulation of transcription is a major way that gene expression is tuned.
Step one of the central dogma
Transcription is the first step of the central dogma of molecular biology — DNA to RNA to protein. By producing an RNA copy of a gene, transcription separates the stable genetic archive (DNA) from the working message (RNA), so that one gene can be transcribed many times and expression can be switched on and off as needed. In cells with a nucleus, the RNA is often processed before leaving the nucleus to be translated.
Research relevance
Understanding and measuring transcription is central to molecular biology, because the set of RNAs a cell makes — its transcriptome — reflects which genes are active. Techniques that quantify transcription, such as RNA sequencing, underpin functional genomics, and the resulting data are shared through repositories under common standards so they can be reused and compared.
Key facts
At a glance
- Definition: copying a gene’s DNA into RNA
- Enzyme: RNA polymerase
- Product: RNA (messenger RNA for protein-coding genes)
- Starts at: a promoter sequence
- Phases: initiation, elongation, termination
- Role: first step of the central dogma
Common questions
FAQ
What happens during transcription?+
During transcription, RNA polymerase reads one strand of a gene’s DNA and builds a complementary RNA copy. The process starts at a promoter and ends at a termination signal, producing an RNA message that can later be translated into protein.
What is the difference between transcription and translation?+
Transcription copies DNA into RNA and is the first step of gene expression. Translation reads that RNA at the ribosome to build a protein and is the second step.
The step most authors miss
Doing CRediT right? Don’t stop at the statement.
A CRediT statement credits you inside one paper. The recognition CRediT was built for happens when those roles are tied to you, persistently. Sign in with your ORCID — free — and claim your CRediT contributions on casrai.org, the home of the standard. They become a verified, portable part of your identity, not a line that disappears into one PDF.
Free: claim your contributions, then export a journal-ready CRediT statement, schema.org structured data, JATS XML, CSV or BibTeX — and preview your public profile. A membership publishes that profile publicly and verifies the journals you serve.
